Answers
Answer:
Option 2
Step-by-step explanation:
The first statement is false because the price for 10 gallons is about $37 from the graph. Using this same reasoning, the third statement is also false. The last statement doesn't make sense because the graph has nothing to do with the amount of miles driven. Therefore, the answer is the second statement. We can prove it by looking at the point (4, 15). This means that it costs $15 for 4 gallons, so then the price for one gallon will be 15 / 4 = $3.75.
Related Questions
Some scientists believe there is a limit to how long humans can live. One supporting argument is that during the past century, life expectancy from age 65 has increased more slowly than life expectancy from birth, so eventually these two will be equal, at which point, according to these scientists, life expectancy should increase no further. In 1900, life expectancy at birth was 45 years, and life expectancy at age 65 was 75 yr. In 2010, these figures had risen to 78.7 and 84.5, respectively. In both cases, the increase in life expectancy has been linear. Using these assumptions and the data given, find the maximum life expectancy for humans.
Answers
Answer:
The maximum life expectancy for humans is approximately 87 years.
Step-by-step explanation:
We have to calculate the point in which both linear functions (Life expectancy from birth and Life expectancy from age 65) intersect, as this is the point in which is estimated to be the maximum life expectancy for humans.
NOTE: to simplify we will consider t=0 to the year 1900, so year 2010 becames t=(2010-1900)=110.
The linear function for Life expectancy from birth can be calculated as:
[tex]t=0\rightarrow y=45\\\\t=110\rightarrow y=78.7\\\\\\m=\dfrac{\Delta y}{\Delta t}=\dfrac{78.7-45}{110-0}=\dfrac{33.7}{110}=0.3064\\\\\\y=0.3064t+45[/tex]
The linear function for Life expectancy from age 65 can be calculated as:
[tex]t=0\rightarrow y=75\\\\t=110\rightarrow y=84.5\\\\\\m=\dfrac{\Delta y}{\Delta t}=\dfrac{84.5-75}{110-0}=\dfrac{9.5}{110}=0.0864\\\\\\y=0.0864t+75[/tex]
Then, the time t where both functions intersect is:
[tex]0.3064t+45=0.0864t+75\\\\(0.3064-0.0864)t=75-45\\\\0.22t=30\\\\t=30/0.22\\\\t=136.36[/tex]
The time t=136.36 corresponds to the year 1900+136.36=2036.36.
Now, we can calculate with any of both functions the maximum life expectancy:
[tex]y=0.0864(136.36)+75\\\\y=11.78+75\\\\y=86.78\approx87[/tex]
The maximum life expectancy for humans is approximately 87 years.
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
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
Please answer this correctly
Answers
4yd^2
2yd^2
6yd^2
Step-by-step explanation:
Rule: height x base/2
The area of the big triangle=2 x 4/2 = 4 yd^2
The area of the small one= 2 x2/2 =2yd^2
The total area of the trapezoid is the sum of these areas= 2+4=6yd^2
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]
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
#SPJ9
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) 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)!
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].
Arun’s restaurant bill is $58, and he wants to leave the waiter an 18 percent tip. What will Arun’s total bill be? $10.44 $47.56 $68.44 $76.00
Answers
Answer:
The Answer is 68.44. I wish it helpsAnswer:
68.44$
Step-by-step explanation:
x=18*58/100=10.44 $(the tip)
58+10.44=68.44 ( the bill )
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]
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]
Which value of x is a solution to the inequality 4x-3<5x+6
Answers
Answer:x greater than -9
Step-by-step explanation:
Which equation can be used to find mMN
Answers
Answer:
Its depending on the angle
Which line is perpendicular to the line Y= -1/3x -2 and passes through the point (1,4)
Answers
Answer:
work is shown and pictured
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.
The sum of three consecutive odd numbers is 315 what are the numbers?
Answers
Answer:
Search Results
Featured snippet from the web
Which means that the first number is 104, the second number is 104 + 1 and the third number is 104 + 2. Therefore, three consecutive integers that add up to 315 are 104, 105, and 106.
Step-by-step explanation:
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
11+11=4
22+22=16
33+33=
What’s the answer
Answers
Answer:
what method exactly r u using ????
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
Can someone please help me with this one??
Answers
Answer:
x = 3.6 cm
Step-by-step explanation:
By the theorem of intersecting secants,
"If two secants are drawn from a point outside the circle, product of the lengths of the secant segment and its external segment are equal."
3(3 + y) = 2(2 + 6 + 3)
9 + 3y = 2 × 11
3y = 22 - 9
3y = 13
y = [tex]\frac{13}{3}[/tex] cm = 4.33 cm
Now we will apply theorem of intersecting chords to determine the value of x.
" When two chords intersect each other in a circle, product of their segments are equal"
[tex]x\times 5=6\times 3[/tex]
[tex]x=\frac{18}{5}[/tex]
[tex]x=3.6[/tex] cm
Therefore, x = 3.6 cm and y = 4.33 cm
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:
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
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
PLEASE ANSWER THIS!
In the diagram, PQRS, JQK and LRK are straight lines
Р
Question 1
Question 2
Question 3
J-
2yQ
Question 4
O
x
K
Question 5
Question 6
Question 7
Question 8
Question 9
M
33°
DO
R
L
2x/
Question 10
S
What is the size of the angle JKL?
Question 11
Question 12
Question 13
Question 14
A Question 15
Question 16
Question 17
Question 18
Question 19
37°
38°
36°
34°
35°
Answers
Answer:
38°
Step-by-step explanation:
The sum of angles that make a line is 180°; the sum of angles in a triangle is 180°. So, we have the following relations:
2x +y +A = 180
2y +x + B = 180
A +B +33 = 180
Adding the first two equations and subtracting the third, we get ...
(2x +y +A) +(2y +x +B) -(A +B +33) = 180 +180 -180
3x +3y -33 = 180
x + y - 11 = 60
x + y = 71
__
We know vertical angles are congruent, so in triangle QRK, we have ...
2y +2x +∠K = 180
∠K = 180 -2x -2y = 180 -2(x +y) = 180 -2(71)
∠JKL = 38°
Answer:
38 degrees
Step-by-step explanation:
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:
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!
