Answers
Answer:
-3 ( x+2i) (x-2i)
Step-by-step explanation:
-3x^2-12
Factor out a -3
-3(x^2 +4)
Rewrite
-3 ( x^2 - -4)
-3 ( x^2 - (-2i)^2) This is the difference of squares ( a^2 -b^2 ) = (a-b)(a+b)
-3 ( x- -2i) (x+2i)
-3( x+2i) (x-2i)
Related Questions
A gas company president for a particular city is interested in the proportion of homes heated by gas. Historically, the proportion of homes heated by gas has been 0.72. A sample of 75 homes was selected and it was found that 45 of them heat with gas. Perform the appropriate test of hypothesis, at level .05, to determine whether the proportion of home heated by gas has changed. Group of answer choices
Answers
Answer:
p-value (0.0208) is less than alpha = 0.05 reject H0.
Step-by-step explanation:
we have the following data:
sample size = n = 75
x, the number to evaluate is 45
the sample proportion would be: x / n = 45/75
p * = 0.6
Now, the null and alternative hypotheses are:
H0: P = 0.72
Ha: P no 72
two tailed test
statistic tes = z = (p * - p) / [(p * (1-p) / n)] ^ (1/2)
replacing we have:
z = (0.6 - 0.72) / [(0.72 * (1-0.72) / 75)] ^ (1/2)
z = -2.31
p-vaule = 2 * p (z <-2.31)
using z table, we get:
p-vaule = 2 * (0.0104)
p-vaule = 0.0208
Therefore, p-value (0.0208) is less than alpha = 0.05 reject H0.
A glucose solution is administered intravenously into the bloodstream at a constant rate r. As the gulcose is added, it is converted into other substances and removed from the bloodstream at a rate that is proportional to the concentration at the time. Thus a model for the concentration C=C(t) of the glucose solution in the bloodstream is
dC/dt=r-kC
Where r an dk are positive constants.
1. Suppose that the concentration at time t=0 is C0. Determine the concentration at any time t by solving the differential equation.
2. Assuming that C0
Answers
Answer:
[tex]C(t) =\dfrac{ r}{k} - \left (\dfrac{r-kC_{0}}{k} \right )e^{ -kt}[/tex]
[tex]C(t) =\dfrac{ r}{k}- e^{ -kt}[/tex] ,thus, the function is said to be an increasing function.
Step-by-step explanation:
Given that:
[tex]\dfrac{dC}{dt}= r-kC[/tex]
[tex]\dfrac{dC}{r-kC}= dt[/tex]
Taking integration on both sides ;
[tex]\int\limits\dfrac{dC}{r-kC}= \int\limits \ dt[/tex]
[tex]- \dfrac{1}{k}In (r-kC)= t +D[/tex]
[tex]In(r-kC) = -kt - kD \\ \\ r- kC = e^{-kt - kD} \\ \\ r- kC = e^{-kt} e^{ - kD} \\ \\r- kC = Ae^{-kt} \\ \\ kC = r - Ae^{-kt} \\ \\ C = \dfrac{r}{k} - \dfrac{A}{k}e ^{-kt} \\ \\[/tex]
[tex]C(t) =\frac{ r}{k} - \frac{A}{k}e^{ -kt}[/tex]
here;
A is an integration constant
In order to determine A, we have [tex]C(0) = C0[/tex]
[tex]C(0) =\frac{ r}{k} - \frac{A}{k}e^{0}[/tex]
[tex]C_0 =\frac{r}{k}- \frac{A}{k}[/tex]
[tex]C_{0} =\frac{ r-A}{k}[/tex]
[tex]kC_{0} =r-A[/tex]
[tex]A =r-kC_{0}[/tex]
Thus:
[tex]C(t) =\dfrac{ r}{k} - \left (\dfrac{r-kC_{0}}{k} \right )e^{ -kt}[/tex]
2. Assuming that C0 < r/k, find lim t→[infinity] C(t) and interpret your answer
[tex]C_{0} < \lim_{t \to \infty }C(t) \\ \\C_0 < \dfrac{r}{k} \\ \\kC_0 <r[/tex]
The equation for C(t) can be rewritten as :
[tex]C(t) =\dfrac{ r}{k} - \left (\dfrac{r-kC_{0}}{k} \right )e^{ -kt}C(t) =\dfrac{ r}{k} - \left (+ve \right )e^{ -kt} \\ \\C(t) =\dfrac{ r}{k}- e^{ -kt}[/tex]
Thus; the function is said to be an increasing function.
(a) There are $n$ chairs in a row. Find the number of ways of choosing $k$ of these chairs, so that no two chosen chairs are adjacent.
(b) There are 10 chairs in a circle, labelled from 1 to 10. Find the number of ways of choosing 3 of these chairs, so that no two chosen chairs are adjacent.
(c) There are $n$ chairs in a circle, labelled from 1 to $n.$ Find the number of ways of choosing $k$ of these chairs, so that no two chosen chairs are adjacent.
Answers
Answer:
(A) P (n,k) = n!/(n-k)! divided by 2
(B) C (n,3) = n!/(12)(n-3)!
(C) C (n,k) = n!/(n-k)!(k!)
Step-by-step explanation:
Permutation deals with order or arrangement or position of objects. Where this does not matter, we use the Combination formula.
We divide by 2 in all cases, because no 2 chosen chairs should be adjacent.
For (B), n=10
C (n,3) = n!/(n-3)!(3!) divided by 2
3! = 3×2×1 = 6
The expression divided by 2 means it will be multiplied by 1/2
Hence 6×2 = 12
And we arrive at
C (n,3) =n!/(12)(n-3)!
Can you help me ? 70 points
Answers
Answer:
5
Step-by-step explanation:
Since the diagonals of a parallelogram bisect each other, the two halves must be equal. Therefore:
[tex]15-x=2x \\\\15=3x \\\\x=5[/tex]
Hope this helps!
Answer:
[tex]x=5[/tex]
Step-by-step explanation:
CE = EB since E is the midpoint of CB (proven by AD intersecting it).
If CE=EB, then:
[tex]2x=15-x\\[/tex]
Add [tex]x[/tex] to both sides
[tex]3x=15\\[/tex]
Divide both sides by 3
[tex]x=5[/tex]
The probability that an event will happen is Upper P (Upper E )equalsStartFraction 13 Over 17 EndFraction . Find the probability that the event will not happen. The probability that the event will not happen is nothing.
Answers
Answer:
The probability that the event will not happen is [tex]\frac{4}{17}[/tex]
Step-by-step explanation:
The occurrence of an event can be divided into two parts, the event would occur or the event would not occur. But the probability of an event is 1.
From the given question;
The probability of the event = 1
The probability that the event will happen, P = [tex]\frac{13}{17}[/tex]
Thus,
The probability that the event will not happen = probability of the event - probability that the event will happen
= 1 - P
= 1 - [tex]\frac{13}{17}[/tex]
= [tex]\frac{17 - 13}{17}[/tex]
= [tex]\frac{4}{17}[/tex]
Thus, the probability that the event will not happen is [tex]\frac{4}{17}[/tex].
A circle has a radius of \blue{3}3start color #6495ed, 3, end color #6495ed. An arc in this circle has a central angle of 20^\circ20 ∘ 20, degrees.
Answers
Answer: The complete question is "A circle has a radius of \blue{3}3start color #6495ed, 3, end color #6495ed. An arc in this circle has a central angle of 20^\circ20 ∘ 20, degrees. What is the length of the arc?"
The length of the arc is 1.06667 units.
Step-by-step explanation:
According to the question the radius of the circle [tex]R=3 \, units[/tex] and central angle of arc is [tex]\Theta =20^{o}[/tex]
As we know that the length of the arc is given as: [tex]L=R\Theta[/tex]
Where R is radius of the circle, L is the length of the arc and [tex]\Theta[/tex] is central angle in radian.
Now, [tex]\Theta =20^{o}\times \frac{\Pi }{180}=\frac{\Pi }{9} \, rad[/tex]
Therefore, length of the arc is
[tex]L=3\times \frac{\Pi }{9}=\frac{\Pi }{3} =\frac{3.14}{3}=1.0466667 \, units[/tex]
–12 + 3b – 1 = –5 – b
Answers
Answer:
2
Step-by-step explanation:
-13+3b=-5-b
4b=8
b=2
Tony rode his bicycle 3 7/10 miles to school. What is this distance written as a decimal?
Answers
Answer:
7/10=0.7
3+0.7=3.7
3.7
Hope this helps
Step-by-step explanation:
Sonya has two red marbles and three yellow marbles. She chooses three marbles at random. What is the probability that she has at least one marble of each color?
Answers
Answer:
90% probability that she has at least one marble of each color
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
The order in which the marbles are selected is not important. So we use the combinations formula to solve this question.
Combinations formula:
[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
What is the probability that she has at least one marble of each color?
Desired outcomes:
Two red(from a set of 2) and one yellow(from a set of 3)
Or
One red(from a set of 2) and two yellows(from a set of 3).
So
[tex]D = C_{2,2}*C_{3,1} + C_{2,1}*C_{3,2} = \frac{2!}{2!(2-2)!}*\frac{3!}{1!(3-1)!} + \frac{2!}{1!(2-1)!}*\frac{3!}{2!(3-2)!} = 3 + 6 = 9[/tex]
Total outcomes:
Three marbles, from a set of 3 + 2 = 5. So
[tex]T = C_{5,3} = \frac{5!}{3!(5-3)!} = 10[/tex]
Probability:
[tex]p = \frac{D}{T} = \frac{9}{10} = 0.9[/tex]
90% probability that she has at least one marble of each color
A recipe submitted to a magazine by one of its subscribers’ states that the mean baking time for a cheesecake is 55 minutes. A test kitchen preparing the recipe before it is published in the magazine makes the cheesecake 10 times at different times of the day in different ovens. The following baking times (in minutes) are observed.
54 55 58 59 59 60 61 61 62 65
Assume that the baking times belong to a normal population. Test the null hypothesis that the mean baking time is 55 minutes against the alternative hypothesis μ > 55. Use α = .05.
Answers
Answer:
[tex]t=\frac{59.4-55}{\frac{3.239}{\sqrt{10}}}=4.296[/tex]
The degrees of freedom are given by:
[tex]df=n-1=10-1=9[/tex]
The p value for this case is given by:
[tex]p_v =P(t_{(9)}>4.296)=0.001[/tex]
And for this case the p value is lower than the significance level so we have enough evidence to reject the null hypothesis and then we can conclude that true mean is higher than 55.
Step-by-step explanation:
Information given
We have the following data: 54 55 58 59 59 60 61 61 62 65
The sample mean and deviation can be calculated with the following formulas:
[tex]\bar X = \frac{\sum_{i=1}^n X_i}{n}[/tex]
[tex]s=\sqrt{\frac{\sum_{i=1}^n (X-i -\bar x)^2}{n-1}}[/tex]
[tex]\bar X=59.4[/tex] represent the sample mean
[tex]s=3.239[/tex] represent the sample standard deviation
[tex]n=10[/tex] sample size
[tex]\alpha=0.05[/tex] represent the significance level
t would represent the statistic
[tex]p_v[/tex] represent the p value
System of hypothesis
We want to test if the true mean is higher than 55, the system of hypothesis would be:
Null hypothesis:[tex]\mu \leq 55[/tex]
Alternative hypothesis:[tex]\mu > 55[/tex]
Replacing the info given we got:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
And replacing the info given we got:
[tex]t=\frac{59.4-55}{\frac{3.239}{\sqrt{10}}}=4.296[/tex]
The degrees of freedom are given by:
[tex]df=n-1=10-1=9[/tex]
The p value for this case is given by:
[tex]p_v =P(t_{(9)}>4.296)=0.001[/tex]
And for this case the p value is lower than the significance level so we have enough evidence to reject the null hypothesis and then we can conclude that true mean is higher than 55
Fraction - Multiplication : (a) 2/9 x 1/13 (b) 12/5 x 35/21
Answers
[tex]answer \\ a. \frac{2}{117} \\ b. 4 \\ solution \\ a. \: \frac{2}{9} \times \frac{1}{13} \\ = \frac{2 \times 1}{9 \times 13} \\ = \frac{2}{117} \\ b. \: \frac{12}{5} \times \frac{35}{21} \\ = divide \: 35 \: by \: 5 \: it \: becomes \\ = 12 \times \frac{7}{21} \\ divide \: 21 \: by \: 7 \: it \: becomes \\ = 12 \times \frac{1}{3} \\ divide \: 12 \: by \: 3 \: it \: becomes \\ = 4 \times 1 \\ = 4 \\ hope \: it \: helps \\ good \: luck \: on \: your \: assignment[/tex]
Answer:
[tex](a) \frac{2}{117} [/tex]
[tex](b)4[/tex]
Step-by-step explanation:
[tex](a) \frac{2}{9} \times \frac{1}{13} \\ = \frac{2}{117} [/tex]
[tex](b) \frac{12}{5} \times \frac{35}{21} \\ = \frac{84}{21} \\ = \frac{28}{7} \\ = 4[/tex]
hope this helps
brainliest appreciated
good luck! have a nice day!
The weights of college football players are normally distributed with a mean of 200 pounds and a standard deviation of 50 pounds. If a college football player is randomly selected, find the probability that he weighs between 170 and 220 pounds.
Answers
Answer:
[tex]P(170<X<220)=P(\frac{170-\mu}{\sigma}<\frac{X-\mu}{\sigma}<\frac{220-\mu}{\sigma})=P(\frac{170-200}{50}<Z<\frac{220-200}{50})=P(-0.6<z<0.4)[/tex]
And we can find this probability with this difference:
[tex]P(-0.6<z<0.4)=P(z<0.4)-P(z<-0.6)=0.655-0.274= 0.381 [/tex]
Step-by-step explanation:
Let X the random variable that represent the weights of a population, and for this case we know the distribution for X is given by:
[tex]X \sim N(200,50)[/tex]
Where [tex]\mu=200[/tex] and [tex]\sigma=50[/tex]
We want to find the following probability:
[tex]P(170<X<220)[/tex]
And we can use the z score formula given by:
[tex]z=\frac{x-\mu}{\sigma}[/tex]
And using this formula we got:
[tex]P(170<X<220)=P(\frac{170-\mu}{\sigma}<\frac{X-\mu}{\sigma}<\frac{220-\mu}{\sigma})=P(\frac{170-200}{50}<Z<\frac{220-200}{50})=P(-0.6<z<0.4)[/tex]
And we can find this probability with this difference:
[tex]P(-0.6<z<0.4)=P(z<0.4)-P(z<-0.6)=0.655-0.274= 0.381 [/tex]
A rectangular piece of paper has a width that is 3 inches less than its length. It is cut in half along a diagonal to create two congruent right triangles with areas of 44 square inches. Which statements are true? Check all that apply.
The area of the rectangle is 88 square inches.
The equation x(x – 3) = 44 can be used to solve for the dimensions of the triangle.
The equation x2 – 3x – 88 = 0 can be used to solve for the length of the rectangle.
The triangle has a base of 11 inches and a height of 8 inches.
The rectangle has a width of 4 inches.
Answers
Answer:
⬇⬇⬇⬇⬇⬇
⬇⬇⬇⬇⬇⬇
Step-by-step explanation:
1, 3, 4
proof below
(1) The area of the rectangle is 88 square inches
(3) The equation x² – 3x – 88 = 0 can be used to solve for the length of the rectangle.
(4) The triangle has a base of 11 inches and a height of 8 inches.
Area of the rectangle
Area of a rectangle is the sum of the area of two equal right triangle.
Area of rectangle = 2(area of right triangle)
Area of rectangle = 2(44 sq inches) = 88 sq inches
Total area of the triangle with respect to length and width of the rectangleLet the length = x
then the width becomes, x - 3
Area = x(x - 3) = 88
x² - 3x = 88
x² - 3x - 88 = 0
x = 11
width = 11 - 3 = 8
Thus, the statements that are true include;
The area of the rectangle is 88 square inchesThe equation x² – 3x – 88 = 0 can be used to solve for the length of the rectangle.The triangle has a base of 11 inches and a height of 8 inches.Learn more about area of rectangle here: https://brainly.com/question/25292087
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WILL GIVE BRAINLIST On a coordinate plane, 2 quadrilaterals are shown. The first figure has points A (negative 2, 1), B (negative 4, 1), C (negative 4, 5), and D (negative 2, 4). Figure 2 has points A prime (2, 1), B prime (4, 1), C prime (4, 5), and D prime (2, 4). What is the rule for the reflection? rx-axis(x, y) → (–x, y) ry-axis(x, y) → (–x, y) rx-axis(x, y) → (x, –y) ry-axis(x, y) → (x, –y)
Answers
Answer:
B) ry-axis(x, y) → (–x, y)
Step-by-step explanation:
Got it right on edge2020 you can trust me :D
A factory produces 1085 nuts per day. Then find the number of nuts that can be
produced in 17days?
Answers
Answer:
1085 nuts per day x 17 days = 18,445 nuts in 17 days
Step-by-step explanation:
Which value of x is a solution to the inequality 4x-3<5x+6
Answers
Answer:x greater than -9
Step-by-step explanation:
Any help would be great
Answers
Answer:
63
Step-by-step explanation: The ratio from planet A to B is 100 to 3. If an elephant weight 2100 is planet a, then we are multiplying 21 to hundred. Whatever you do on the left side you have to do it on the right side and if you multiply 21 and 3 on the right side then you get 63.
Answer:
63 pounds
Step-by-step explanation:
The ratio for Planet A to Planet B is
100 : 3
Creating a proportionality with the unknown as x
=> [tex]\frac{100}{3} = \frac{2100}{x}[/tex]
Isolating x would give
x = [tex]\frac{2100 * 3}{100}[/tex]
x = 21 × 3
x = 63 pounds
Can anyone help me with the answer please
Answers
Answer:
Graph D
Step-by-step explanation:
First, look at the x-intercepts (where the graph touches the x-axis): x= -1 and x= 3
This rules out Graph B and C which have x-intercepts at x= -3 and x= -1
Next, look at the y-intercept (where the graph touches the y-axis): y= -3
This rules out Graph A which has a y-intercept at y= 3
4 lines are shown. A line with points A, F, D intersects with a line with points B, F, E at point F. A line extends from point F to point G between angle E F D. Another line extends from point F to point D in between angle B F D. In the diagram, which angle is part of a linear pair and part of a vertical pair? AngleBFC AngleCFG AngleGFD AngleEFA
Answers
Based on the above, the angle that is said to be a part of a linear pair and part of a vertical pair is Angle EFA.
What are linear pair and part of a vertical pair?If two angles is said to create a linear pair, the angles are then regarded as supplementary and it is said that their measures often add up to 180°.
Note that Vertical angles are said to be pair of nonadjacent angles created by the crossing or the intersection of any two straight lines.
Since vertical angles are seen if "X" created by two straight lines then when you look at the image attached, you can see that the angle that can from this is Angle EFA.
Therefore, Based on the above, the angle that is said to be a part of a linear pair and part of a vertical pair is Angle EFA.
Learn more about vertical pair from
https://brainly.com/question/14362353
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Please help me. I’ll mark you as brainliest if correct
Answers
Answer:
b = -18
Step-by-step explanation:
(3 + 4i) (-3-2i)
When we foil:
-9 + -6i + -12i + -8i^2
-8i^2 = +8
Combine like terms:
-1 + -18i
What is the equation of the line that is parallel to the given
line and passes through the point (-4,-6 )?
x= -6
x=-4
y=-6
y=-4
Answers
Answer:
The line on the graph is y = 4, where no matter what the value of x is, the value of y will always be 4. Therefore, any line parallel to this one will be y = ?. If it passes through (-4, -6), that means that the equation is y = -6.
Answer:
С)))) Y= -6
Step-by-step explanation:
just did on edg. :D
The length of a field is twice it's breadth. If the length is 30cm. Calculate the perimeter of the field.
Answers
Answer:
b=30/2=15
peri= 90
Step-by-step explanation:
A: What are the solutions to the quadratic equation x2+9=0? B: What is the factored form of the quadratic expression x2+9? Select one answer for question A, and select one answer for question B. B: (x+3)(x−3) B: (x+3i)(x−3i) B: (x−3i)(x−3i) B: (x+3)(x+3) A: x=3 or x=−3 A: x=3i or x=−3i A: x=3 A: x=−3i
Answers
Answer:
A. The solutions are [tex]x=3i,\:x=-3i[/tex].
B. The factored form of the quadratic expression [tex]x^2+9=(x-3i)(x+3i)[/tex]
Step-by-step explanation:
A. To find the solutions to the quadratic equation [tex]x^2+9=0[/tex] you must:
[tex]\mathrm{Subtract\:}9\mathrm{\:from\:both\:sides}\\\\x^2+9-9=0-9\\\\\mathrm{Simplify}\\\\x^2=-9\\\\\mathrm{For\:}x^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}x=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}\\\\x=\sqrt{-9},\:x=-\sqrt{-9}[/tex]
[tex]x=\sqrt{-9} = \sqrt{-1}\sqrt{9}=\sqrt{9}i=3i\\\\x=-\sqrt{-9}=-\sqrt{-1}\sqrt{9}=-\sqrt{9}i=-3i[/tex]
The solutions are:
[tex]x=3i,\:x=-3i[/tex]
B. Two expressions are equivalent to each other if they represent the same value no matter which values we choose for the variables.
To factor [tex]x^2+9[/tex]:
First, multiply the constant in the polynomial by [tex]i^2[/tex] where [tex]i^2[/tex] is equal to -1.
[tex]x^2+9i^2[/tex]
Since both terms are perfect squares, factor using the difference of squares formula
[tex]a^2-i^2=(a+i)(a-i)[/tex]
[tex]x^2+9=x^2+9i^2=\left(-3i+x\right)\left(3i+x\right)[/tex]
11+11=4
22+22=16
33+33=
What’s the answer
Answers
Answer:
what method exactly r u using ????
find the perimeter of this figure to the nearest hundredth use 3.14 to approximate pi P=?ft
Answers
Answer:
105.13ft^2
Step-by-step explanation:
[tex]A=lw\\=10*8\\=80ft^2[/tex]
Rectangle
[tex]A=\frac{1}{2} \pi r^2\\=\frac{1}{2\pi } 4^2\\=25.13[/tex]
Add both together
80+25.13
=105.13
Answer : 105.13
Step-by-step explanation:
Identify the type of data (qualitative/quantitative) and the level of measurement for the following variable. Explain. The average mass (in grams )of a sample of rocks collected in the waters of a region.
1. Are the data qualitative or quantitative?
A. Qualitative, because descriptive terms are used to measure or classify the data.
B. Quantitative, because descriptive terms are used to measure or classify the data.
C. Qualitative, because numerical values, found by either measuring or counting, are used to describe the data.
D. Quantitative, because numerical values, found by either measuring or counting, are used to describe the data.
2. What is the data set's level of measurement?
A. Ratio, because the differences in the data can be meaningfully measured, and the data have a true zero point.
B. Interval, because the differences in the data can be meaningfully measured, but the data do not have a true zoro point.
C. Nominal, because the data are categories or labels that cannot be ranked.
D. Ordinal, because the data are categories or labels that can be ranked.
3. What is the probability of randomly selecting a diamond from a standard 52-card deck?The probability of selecting a diamond is 0.25.
4. Use the contingency table to complete parts a) through d) below.
Event A Event B
Event C 10 11
Event D 3 4
Event E 14 8
A) Determine the probability of P(AIC).
B) Determine the probability of P(CIA).
C) Determine the probability of P(BE).
5. Use the contingency table to complete parts a) through d) below.
Event A Event B
Event C 10 11
Event D 3 4
Event E 14 8
A) Determine the probability of P(CIA).
B) Determine the probability of P(BE).
C( Determine the probability of P(EB).
Answers
Answer:
Step-by-step explanation:
Hello!
The variable is
X: average mass of a sample of rocks collected in the waters of a region. (measured in grams)
Variables can be:
Quantitative: they represent number, any characteristic that can be "counted" is a quantitative variable, the most common examples are weight, volume, temperature, height, etc...
There are two types of quantitative variables:
⇒ Discrete variables: The only take certain values within the interval of definition of the variable, for example "number of sales" or "money in a wallet"
⇒ Continuous variables: They can take any value within an interval, in this example that you are working with mass, depending on the precision of the scale the mass can have infinite decimal values.
Qualitative: they represent characteristics that cannot be counted, meaning, they are not represented by numbers. There are many attributes that are qualitative variables, for example: colors, race of an animal, phenotypes, types of business, etc...
1)
The variable in this example is Quantitative, it takes numerical values, and the correct option is:
D. Quantitative, because numerical values, found by either measuring or counting, are used to describe the data.
2)
The values of mass of the rocks can take any value within the range of definition of the variable, they only depend on the precision of the scale used to weight the rocks.
B. Interval, because the differences in the data can be meaningfully measured, but the data do not have a true zero point.
3)
A standard 52-card deck contains 13 cards for each suit (clubs, diamonds, hearts and spades)
To calculate the probability of choosing a card at random and it being a Diamond, supposing that all cards are equally probable, you have to divide the total number of diamonds by the total number of cards in the deck:
P(diamond)= 13/52= 0.25
For items 4) and 5) the contingency tables are attached.
4)
a. and b. are conditional probabilities, to calculate them you have to apply the following formula: [tex]P(A|B)= \frac{P(AnB)}{P(B)}[/tex]
This means that the probability of the event "A" given that event "B" has occurred is equal to the probability of the intersection between events "A" and "B" divided by the probability of event "B"
a. P(A|C)= [tex]\frac{P(AnC)}{P(C)}[/tex]
To calculate the probability of the intersection P(A∩C) you have to divide the observations where both events cross by the total of observations on the table:
P(A∩C)= 10/50= 0.20
The probability of C is found in the margins of the table, in this case you have to divide the total of observations for event C by the total of observations of the table:
P(C)= 21/50= 0.42
Now you can calculate the asked probability:
[tex]P(A|C)= \frac{0.2}{0.42}= 0.48[/tex]
b. P(C|A)= [tex]\frac{P(AnC)}{P(A)}[/tex]
From item a. we already know that P(A∩C)= 10/50= 0.20
The probability of event A is in the margin of the table and you calculate it as:
P(A)= 27/50= 0.54
Then:
[tex]P(C|A)= \frac{0.20}{0.54} = 0.37[/tex]
c. P(BE)
This symbolized the probability of the events "B" and "E" occurring at the same time, you can also symbolize it as P(B∩E)
To calculate the probability of B and E happening you have to do as follows:
P(B∩E)= 8/50= 0.16
5)
a. P(C|A)= 0.37 (As calculated in 4b.)
b. P(BE) and c. P(EB) ⇒ Both expressions symbolize the intersection between events "B" and "E", P(B∩E)= P(E∩B)= 0.16 (As calculated in 4c.)
I hope this helps!
Find x
PLEASE HELP ME !! 11 POINTS !
Answers
Answer:
5
Step-by-step explanation:
Since this is a right triangle we can use trig functions
sin theta = opp /hyp
sin 30 = x / 10
10 sin 30 = x
10 * 1/2 = x
5 =x
The president of a university claimed that the entering class this year appeared to be larger than the entering class from previous years but their mean SAT score is lower than previous years. He took a sample of 20 of this year's entering students and found that their mean SAT score is 1,501 with a standard deviation of 53. The university's record indicates that the mean SAT score for entering students from previous years is 1,520. He wants to find out if his claim is supported by the evidence at a 5% level of significance. True or False: The null hypothesis would be rejected.
Answers
Answer:
False.
The null hypothesis failed to be rejected.
At a significance level of 5%, there is not enough evidence to support the claim that the entering class has a mean SAT score that is significantly lower than 1520.
Step-by-step explanation:
This is a hypothesis test for the population mean.
The claim is that the entering class has a mean SAT score that is significantly lower than 1520.
Then, the null and alternative hypothesis are:
[tex]H_0: \mu=1520\\\\H_a:\mu< 1520[/tex]
The significance level is 0.05.
The sample has a size n=20.
The sample mean is M=1501.
As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=53.
The estimated standard error of the mean is computed using the formula:
[tex]s_M=\dfrac{s}{\sqrt{n}}=\dfrac{53}{\sqrt{20}}=11.851[/tex]
Then, we can calculate the t-statistic as:
[tex]t=\dfrac{M-\mu}{s/\sqrt{n}}=\dfrac{1501-1520}{11.851}=\dfrac{-19}{11.851}=-1.6[/tex]
The degrees of freedom for this sample size are:
[tex]df=n-1=20-1=19[/tex]
This test is a left-tailed test, with 19 degrees of freedom and t=-1.6, so the P-value for this test is calculated as (using a t-table):
[tex]\text{P-value}=P(t<-1.6)=0.063[/tex]
As the P-value (0.063) is bigger than the significance level (0.05), the effect is not significant.
The null hypothesis failed to be rejected.
There is not enough evidence to support the claim that the entering class has a mean SAT score that is significantly lower than 1520.
Solve the inequality -1/2x -3 ≤ -2.5
Answers
Answer:
x ≥-1
Step-by-step explanation:
-1/2x -3 ≤ -2.5
Add 3 to each side
-1/2x -3+3 ≤ -2.5+3
-1/2x ≤ .5
Multiply each side by -2, remembering to flip the inequality
-2 * -1/2x ≥ 1/2 * -2
x ≥-1
"Children under the age of 13 are not allowed to operate a boat." Part A: Write an inequality to show the age of children who are allowed to operate a boat. (5 points) Part B: Describe in words how you can show the solution to this inequality on a number line. (5 points)
Answers
Answer:
X ≤ 13
Step-by-step explanation:
Part A: X ≤ 13
Part B: Draw a closed circle from 13 and up on the number line.
Make the arrow look like this >.
The inequality will be x ≥ 13. The age of the person should be greater than or equal to 13.
What is inequality?Inequality is defined as an equation that does not contain an equal sign. Inequality is a term that describes a statement's relative size and can be used to compare these two claims.
“Children under the age of 13 are not allowed to operate a boat.”
Let x be the age of the person.
The inequality to show the age of children who are allowed to operate a boat will be
x ≥ 13
The age of the person should be greater than or equal to 13.
More about the inequality link is given below.
https://brainly.com/question/19491153
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