Answer:
a) -x2 , -(x2)
b)3x-7 , (3x) - 7
c) -2x+8 , -(2x-8)
A 10-item statistics quiz was given to 30 students. The table below gives the scores received along with the corresponding frequencies.
A 2-column table with 6 rows. Column 1 is labeled score with entries 5, 6, 7, 8, 9, 10. Column 2 is labeled Frequency with entries 1, 2, 5, 5, 7, 10.
What was the mean score on the quiz?
7.5
8.5
9
10
Answer:
Should be (B).
8.5
ED2021
Answer: B
Step-by-step explanation:
Which points lie on the graph of f(x) = loggx?
Check all that apply.
Step-by-step explanation:
f(x)=log(x)
=d(log(x)/dx)
=>y=1/x
A computer system uses passwords that are exactly six characters and each character is one of the 26 letters (a–z) or 10 integers (0–9). Suppose that 10,000 users of the system have unique passwords. A hacker randomly selects (with replace- ment) one billion passwords from the potential set, and a match to a user’s password is called a hit. (a) What is the distribution of the number of hits? (b) What is the probability of no hits? (c) What are the mean and variance of the number of hits?
Answer:
The number of hits would follow a binomial distribution with [tex]n =10,\!000[/tex] and [tex]p \approx 4.59 \times 10^{-6}[/tex].
The probability of finding [tex]0[/tex] hits is approximately [tex]0.955[/tex] (or equivalently, approximately [tex]95.5\%[/tex].)
The mean of the number of hits is approximately [tex]0.0459[/tex]. The variance of the number of hits is approximately [tex]0.0459\![/tex] (not the same number as the mean.)
Step-by-step explanation:
There are [tex](26 + 10)^{6} \approx 2.18 \times 10^{9}[/tex] possible passwords in this set. (Approximately two billion possible passwords.)
Each one of the [tex]10^{9}[/tex] randomly-selected passwords would have an approximately [tex]\displaystyle \frac{10,\!000}{2.18 \times 10^{9}}[/tex] chance of matching one of the users' password.
Denote that probability as [tex]p[/tex]:
[tex]p := \displaystyle \frac{10,\!000}{2.18 \times 10^{9}} \approx 4.59 \times 10^{-6}[/tex].
For any one of the [tex]10^{9}[/tex] randomly-selected passwords, let [tex]1[/tex] denote a hit and [tex]0[/tex] denote no hits. Using that notation, whether a selected password hits would follow a bernoulli distribution with [tex]p \approx 4.59 \times 10^{-6}[/tex] as the likelihood of success.
Sum these [tex]0[/tex]'s and [tex]1[/tex]'s over the set of the [tex]10^{9}[/tex] randomly-selected passwords, and the result would represent the total number of hits.
Assume that these [tex]10^{9}[/tex] randomly-selected passwords are sampled independently with repetition. Whether each selected password hits would be independent from one another.
Hence, the total number of hits would follow a binomial distribution with [tex]n = 10^{9}[/tex] trials (a billion trials) and [tex]p \approx 4.59 \times 10^{-6}[/tex] as the chance of success on any given trial.
The probability of getting no hit would be:
[tex](1 - p)^{n} \approx 7 \times 10^{-1996} \approx 0[/tex].
(Since [tex](1 - p)[/tex] is between [tex]0[/tex] and [tex]1[/tex], the value of [tex](1 - p)^{n}[/tex] would approach [tex]0\![/tex] as the value of [tex]n[/tex] approaches infinity.)
The mean of this binomial distribution would be:[tex]n\cdot p \approx (10^{9}) \times (4.59 \times 10^{-6}) \approx 0.0459[/tex].
The variance of this binomial distribution would be:
[tex]\begin{aligned}& n \cdot p \cdot (1 - p)\\ & \approx(10^{9}) \times (4.59 \times 10^{-6}) \times (1- 4.59 \times 10^{-6})\\ &\approx 4.59 \times 10^{-6}\end{aligned}[/tex].
simplify 7-(3n+6)+10n
Answer:
1 + 7n
Step-by-step explanation:
7-(3n+6)+10n
7 - 3n - 6 + 10 n
1 - 7n
Answered by Gauthmath
Air is being pumped into a spherical balloon at a rate of 5 cm^3/min. Determine the rate at which the radius of the balloon is increasing when the diameter of the balloon is 20 cm
0.08 cm/min
Step-by-step explanation:
Given:
[tex]\dfrac{dV}{dt}=5\:\text{cm}^3\text{/min}[/tex]
Find [tex]\frac{dr}{dt}[/tex] when diameter D = 20 cm.
We know that the volume of a sphere is given by
[tex]V = \dfrac{4\pi}{3}r^3[/tex]
Taking the time derivative of V, we get
[tex]\dfrac{dV}{dt} = 4\pi r^2\dfrac{dr}{dt} = 4\pi\left(\dfrac{D}{2}\right)^2\dfrac{dr}{dt} = \pi D^2\dfrac{dr}{dt}[/tex]
Solving for [tex]\frac{dr}{dt}[/tex], we get
[tex]\dfrac{dr}{dt} = \left(\dfrac{1}{\pi D^2}\right)\dfrac{dV}{dt} = \dfrac{1}{\pi(20\:\text{cm}^2)}(5\:\text{cm}^3\text{/min})[/tex]
[tex]\:\:\:\:\:\:\:= 0.08\:\text{cm/min}[/tex]
Find the missing segment in the image below
I NEED HELP THANK YOU!!
Answer:
rt3/2
Step-by-step explanation:
first off cosine is the x coordinate
now if you do't want to use a calculator, you can use use the unit circle.
360 - 330 = 30 (360 degrees is a whole circle)
a 30 60 90 triangle is made, then use the law for 30 60 90 triangles:
if the shortest leg is x, the other leg is x*rt3 and the hypotenuse is 2x.
Answer:
D
Step-by-step explanation:
cos 330 = cos (360-330)
= cos 30
= √3 /2
find the equation of Straight line which passes through the point A(-5,10) makes equal intercept on both axes.
Answer:
y = -x + 5
Step-by-step explanation:
The point is in quadrant 2, so the line must pass through points that look like (a, 0) and (0, a) where a is a positive number. The slope of such a line is -1.
If (x, y) is a point on the line, then the slope between points (x, y) and (-5, 10) is 1, and you can write
[tex]\frac{y-10}{x-(-5)}=-1\\y-10 = -1(x+5)\\y-10=-x-5\\y=-x+5[/tex]
Find the missing side lengths leave your answer as a racials simplest form
Answer:
m=[tex]7\sqrt3[/tex]
n=7
Step-by-step explanation:
Hi there!
We are given a right triangle (notice the 90°) angle, the measure of one of the acute angles as 60°, and the measure of the hypotenuse (the side OPPOSITE from the 90 degree angle) as 14
We need to find the lengths of m and n
Firstly, let's find the measure of the other acute angle
The acute angles in a right triangle are complementary, meaning they add up to 90 degrees
Let's make the measure of the unknown acute angle x
So x+60°=90°
Subtract 60 from both sides
x=30°
So the measure of the other acute angle is 30 degrees
This makes the right triangle a special kind of right triangle, a 30°-60°-90° triangle
In a 30°-60°-90° triangle, if the length of the hypotenuse is a, then the length of the leg (the side that makes up the right angle) opposite from the 30 degree angle is [tex]\frac{a}{2}[/tex], and the leg opposite from the 60 degree angle is [tex]\frac{a\sqrt3}{2}[/tex]
In this case, a=14, n=[tex]\frac{a}{2}[/tex], and m=[tex]\frac{a\sqrt3}{2}[/tex]
Now substitute the value of a into the formulas to find n and m to find the lengths of those sides
So that means that n=[tex]\frac{14}{2}[/tex], which is equal to 7
And m=[tex]\frac{14\sqrt3}{2}[/tex], which simplified, is equal to [tex]7\sqrt3[/tex]
Hope this helps!
Plot the following equation using the x- and y-intercepts.
2y+6=0
If both intercepts are zero, find at least one other point. Identify the graph of this equation.
Answer:
option 2
Step-by-step explanation:
What is the slope of the line that passes through the points (4, 10) and (1,10)?
Write
your answer in simplest form.
Answer:
0
Step-by-step explanation:
We have two points so we can use the sloe formula
m = (y2-y1)/(x2-x1)
= ( 10-10)/(1-4)
= 0/ -3
= 0
Answer:
Slope is 0
explanation:
Slope is the same as gradient.
Formular:
[tex]{ \boxed{ \bf{slope = \frac{y _{2} - y _{1}}{x _{2} - x _{1} } }}}[/tex]
Substitute the variables:
[tex]{ \tt{slope = \frac{10 - 10}{1 - 4} }} \\ \\ = { \tt{ \frac{0}{ - 3} }} \\ = 0[/tex]
Find the Z scores for which 5% of the distributions area lies between negative Z & Z
Answer:
0.475: Z = -0.062706778
0.525: Z = 0.062706778
Step-by-step explanation:
What is the area of this triangle?
Enter your answer in the box.
units2
Answer:
8 units^2
Step-by-step explanation:
The area of a tringle is 1/2 bh. The base, LK, measures 4 while the height is also 4(you can get these values by counting the squares). This means the area is:
1/2 * (4)(4) = 1/2 * 16 = 8 units^2
Last Thursday, each of the students in M. Fermat's class brought one piece of fruit to school. Each brought an apple, a banana, or an orange. In total, 20% of the students brought an apple and 35% brought a banana. If 9 students brought oranges, how many students were in the class
Answer:
20 students
Step-by-step explanation:
Step 1:
Calculate the percentage of students who brought oranges by taking away the percentage of students who brought bananas and apples from the total percentage of students.
100-(20+35)
=45
Step 2:
Equate the percentage of students who brought oranges to the number of students who brought oranges
45%=9
100%
(100×9)/45
=20 students
A train leaves the station and has to travel 486km. The train maintains a speed of 120km. After travelling for 3 hours and 15 minutes, how much further does the train have to travel to reach its destination?
Answer:
I think its 2 hours 30 minutes
Step-by-step explanation:
Which ratio is equal to 27 : 81?
Answer:
1:3
Step-by-step explanation:
27 : 81
Divide each side by 27
27/27 : 81/27
1:3
The median for the given set of six ordered data values is 29.5
9 12 25_ 41 50
What is the missing value?
Answer:
34
Step-by-step explanation:
let the missing value is x
(25+x) /2 = 29.5
25+x = 29.5(2)
25+x = 59
x = 59-25
x = 34
Which statement is sufficient to prove that quadrilateral ABCD is a parallelogram?
A) m∠A ≅ m∠C, m∠B ≅ m∠D
B) AB ≅ CD
C) AC ≅ BD
D) BC // AD
Answer:
A) m∠A ≅ m∠C, m∠B ≅ m∠D
Step-by-step explanation:
If both pairs of opposite angles are congruent, then the figure is a parallelogram.
What is the equation of a circle with center (1, -4) and radius 2?
Answer:
(x-1)^2 + (y+4)^2 = 4
Step-by-step explanation:
The equation for a circle is given by
(x-h)^2 + (y-k)^2 = r^2 where (h,k) is the center and r is the radius
(x-1)^2 + (y- -4)^2 = 2^2
(x-1)^2 + (y+4)^2 = 4
find the area of the regular polygon
Answer:
A = 374.123 ft^2
Step-by-step explanation:
First, lets calculate the perimeter:
Perimeter (p) = side length (s) * number of sides (n)
[tex]p = s * n[/tex]
[tex]p = 12 * 6[/tex]
[tex]p = 72[/tex]
Next, lets find the apothem, which is the shortest length from any side to the middle. It's like the radius in a circle, but more complicated.
Apothem (a) = side length (s) / ( 2 * tan(180/number of sides (n)) )
[tex]a = \frac{s}{2 * tan (\frac{180}{n} )}[/tex]
[tex]a = \frac{12}{2 * tan (\frac{180}{6} )}[/tex]
[tex]a = \frac{12}{2 * \frac{\sqrt{3} }{3}}[/tex]
[tex]a = \frac{12}{\frac{2\sqrt{3} }{3}}[/tex]
[tex]a = \frac{12*3}{2\sqrt{3}}[/tex]
[tex]a = \frac{6*3}{\sqrt{3}}[/tex]
[tex]a = \frac{18}{\sqrt{3}}[/tex]
Now, finally, to find the area of a regular polygon, we use the following equation:
Area (A) = ( apothem (a) * perimeter (p) ) / 2
[tex]A = \frac{a * p}{2}[/tex]
[tex]A = \frac{\frac{18}{\sqrt{3} } * 72}{2}[/tex]
[tex]A = \frac{18}{\sqrt{3}} * 36[/tex]
[tex]A = \frac{640}{\sqrt{3}}[/tex]
Turning into a decimal:
[tex]A = 374.123 ft ^2[/tex]
Help me plz plz help me with this question
Answer:
6 97/100 bags
Step-by-step explanation:
4 1/10 ⋅ 1 7/10 = ?
41/10 ⋅ 17/10 = 697/100
697/100 = 6 97/100
6 97/100 bags
Answer:
697/100 bags
or
6 97/100 bags
Step-by-step explanation:
it is fractions. just plain and simple.
when you eat a pizza slice, it is usually one of 8 slices that make the whole pizza. 1/8 or one 8th. meaning that the whole thing is 8/8 or eight 8ths.
the same for 10ths or any other fractions.
4 1/10 bags = 41/10 bags
1 7/10 times = 17/10 times
and now we multiply fractions, as 17/10 times is similar to 2 times or 3 times something - we multiply by this factor.
41/10 × 17/10
as we learned in early elementary school : numerators (top part of the fraction) are multiplied with each other, and denominators (bottom part) are multiplied with each other. and then we simplify the result as much as possible.
41/10 × 17/10 = (41×17) / (10×10) = 697/100
no simplification is possible, sadly.
but that means he used almost 7 bags of hot dog buns.
exactly 6 full bags and 97/100 of the 7th bag.
so, either
697/100 bags
or
6 97/100 bags
or as alternative (not wanted here in this example but just FYI)
6.97 bags
A scale drawn on the map shows that 1 inch represents 40 miles. If tuo cities
are 25 inches apart on the map, what is the distance between them in real
life?
Answer:
Im pretty sure its 1,000 miles (dont forget the unit)
Step-by-step explanation:
Determine if this problem is a inverse variation or direct variation problem! This means that:
equation would be:
1=40
25=x
cross multiply*
x=25*40
x=1,000 miles apart! (dont forget the unit)
If this doesnt work then try this equation!
1=40
25=x
Multiply 1*40 and 25 *x
40=25x......
40/25= 1.6
x=1.6! (Extra step)
Cheers!
Answer: 100 Miles
Step-by-step explanation: took the miles and got it correct.
(Also it's 2.5 inches apart, not 25.)
Young's modulus is a quantitative measure of stiffness of an elastic material. Suppose that for metal sheets of a particular type, its mean value and standard deviation are 75 GPa and 1.7 GPa, respectively. Suppose the distribution is normal. (Round your answers to four decimal places.)
Required:
a. Calculate P(79 <= P <= 81) when n = 25.
b. How likely is it that the sample mean diameter exceeds 81 when n = 36?
Answer:
a) P(79 <= P <= 81) = 0.9968
b) P( X > 81 ) = 0.0002
Step-by-step explanation:
mean value = 75 GPa
standard deviation = 1.7 GPa
a) Determine P(79 <= P <= 81)
given that : n = 25
attached below is the detailed solution
P(79 <= P <= 81) = 0.9968
b) Determine how likely the sample mean diameter will exceed 81
given that n = 36
mean diameter = 81
P( X > 81 ) = 0.0002
find the mid-point of the line segment joining the points (10, 13) and (-7, 7)?
Answer:
(3/2,10)
Step-by-step explanation:
Mid point is ((10-7)/2,(13+7)/2)=(1.5,10)
Which of the following behaviors would best describe someone who is listening and paying attention? a) Leaning toward the speaker O b) Interrupting the speaker to share their opinion c) Avoiding eye contact d) Asking questions to make sure they understand what's being said
The answer is A and D
good luck
lim ₓ→∞ (x+4/x-1)∧x+4
It looks like the limit you want to find is
[tex]\displaystyle \lim_{x\to\infty} \left(\frac{x+4}{x-1}\right)^{x+4}[/tex]
One way to compute this limit relies only on the definition of the constant e and some basic properties of limits. In particular,
[tex]e = \displaystyle\lim_{x\to\infty}\left(1+\frac1x\right)^x[/tex]
The idea is to recast the given limit to make it resemble this definition. The definition contains a fraction with x as its denominator. If we expand the fraction in the given limand, we have a denominator of x - 1. So we rewrite everything in terms of x - 1 :
[tex]\left(\dfrac{x+4}{x-1}\right)^{x+4} = \left(\dfrac{x-1+5}{x-1}\right)^{x-1+5} \\\\ = \left(1+\dfrac5{x-1}\right)^{x-1+5} \\\\ =\left(1+\dfrac5{x-1}\right)^{x-1} \times \left(1+\dfrac5{x-1}\right)^5[/tex]
Now in the first term of this product, we substitute y = (x - 1)/5 :
[tex]\left(\dfrac{x+4}{x-1}\right)^{x+4} = \left(1+\dfrac1y\right)^{5y} \times \left(1+\dfrac5{x-1}\right)^5[/tex]
Then use a property of exponentiation to write this as
[tex]\left(\dfrac{x+4}{x-1}\right)^{x+4} = \left(\left(1+\dfrac1y\right)^y\right)^5 \times \left(1+\dfrac5{x-1}\right)^5[/tex]
In terms of end behavior, (x - 1)/5 and x behave the same way because they both approach ∞ at a proportional rate, so we can essentially y with x. Then by applying some limit properties, we have
[tex]\displaystyle \lim_{x\to\infty} \left(\frac{x+4}{x-1}\right)^{x+4} = \lim_{x\to\infty} \left(\left(1+\dfrac1x\right)^x\right)^5 \times \left(1+\dfrac5{x-1}\right)^5 \\\\ = \lim_{x\to\infty}\left(\left(1+\dfrac1x\right)^x\right)^5 \times \lim_{x\to\infty}\left(1+\dfrac5{x-1}\right)^5 \\\\ =\left(\lim_{x\to\infty}\left(1+\dfrac1x\right)^x\right)^5 \times \left(\lim_{x\to\infty}\left(1+\dfrac5{x-1}\right)\right)^5[/tex]
By definition, the first limit is e and the second limit is 1, so that
[tex]\displaystyle \lim_{x\to\infty} \left(\frac{x+4}{x-1}\right)^{x+4} = e^5\times1^5 = \boxed{e^5}[/tex]
You can also use L'Hopital's rule to compute it. Evaluating the limit "directly" at infinity results in the indeterminate form [tex]1^\infty[/tex].
Rewrite
[tex]\left(\dfrac{x+4}{x-1}\right)^{x+4} = \exp\left((x+4)\ln\dfrac{x+4}{x-1}\right)[/tex]
so that
[tex]\displaystyle \lim_{x\to\infty} \left(\frac{x+4}{x-1}\right)^{x+4} = \lim_{x\to\infty}\exp\left((x+4)\ln\dfrac{x+4}{x-1}\right) \\\\ = \exp\left(\lim_{x\to\infty}(x+4)\ln\dfrac{x+4}{x-1}\right) \\\\ =\exp\left(\lim_{x\to\infty}\frac{\ln\dfrac{x+4}{x-1}}{\dfrac1{x+4}}\right)[/tex]
and now evaluating "directly" at infinity gives the indeterminate form 0/0, making the limit ready for L'Hopital's rule.
We have
[tex]\dfrac{\mathrm d}{\mathrm dx}\left[\ln\dfrac{x+4}{x-1}\right] = -\dfrac5{(x-1)^2}\times\dfrac{1}{\frac{x+4}{x-1}} = -\dfrac5{(x-1)(x+4)}[/tex]
[tex]\dfrac{\mathrm d}{\mathrm dx}\left[\dfrac1{x+4}\right]=-\dfrac1{(x+4)^2}[/tex]
and so
[tex]\displaystyle \exp\left(\lim_{x\to\infty}\frac{\ln\dfrac{x+4}{x-1}}{\dfrac1{x+4}}\right) = \exp\left(\lim_{x\to\infty}\frac{-\dfrac5{(x-1)(x+4)}}{-\dfrac1{(x+4)^2}}\right) \\\\ = \exp\left(5\lim_{x\to\infty}\frac{x+4}{x-1}\right) \\\\ = \exp(5) = \boxed{e^5}[/tex]
A survey of 30-year-old males provided data on the number of auto accidents in the previous 5 years. The sample mean is 1.3 accidents per male. Test the hypothesis that the number of accidents follows a Poisson distribution at the 5% level of significance.
No. of accident No. of males
0 39
1 22
2 14
3 11
>=4 4
Required:
a. What's the Expected probability of finding males with 0 accidents?
b. What's the Expected probability of finding males with 4 or more accidents?
Answer:
0.2725
0.0431
Step-by-step explanation:
The distribution here is a poisson distribution :
λ = 1.3
The poisson distribution :
p(x) = [(e^-λ * λ^x)] ÷ x!
Expected probability of finding male with 0 accident ; x = 0
p(0) = [(e^-1.3 * 1.3^0)] ÷ 0!
p(0) = [0.2725317 * 1] ÷ 1
p(0) = 0.2725317
= 0.2725
2.)
P(x ≥ 4) = 1 - P(x < 4)
P(x < 4) = p(x = 0) + p(x. = 1) + p(x = 2) + p(x = 3)
p(x = 0) = p(0) = [(e^-1.3 * 1.3^0)] ÷ 0! = 0.2725
p(x = 1) = p(1) = [(e^-1.3 * 1.3^1)] ÷ 1! = 0.35429
p(x = 2) = p(2) = [(e^-1.3 * 1.3^2)] ÷ 2! = 0.23029 p(x = 3) = p(3) = [(e^-1.3 * 1.3^3)] ÷ 0! = 0.09979
P(x < 4) = 0.2725 + 0.35429 + 0.23029 + 0.09979 = 0.95687
P(x ≥ 4) = 1 - 0.95687 = 0.0431
The scatterplot shows the attendance at a pool for different daily high temperatures.
A graph titled pool attendance has temperature (degrees Fahrenheit) on the x-axis, and people (hundreds) on the y-axis. Points are at (72, 0.8), (75, 0.8), (77, 1.1), (82, 1.4), (87, 1.5), (90, 2.5), (92, 2.6), (95, 2.6), (96, 2.7). An orange point is at (86, 0.4).
Complete the statements based on the information provided.
The scatterplot including only the blue data points shows
✔ a strong positive
association. Including the orange data point at (86, 0.4) would
✔ weaken
the correlation and
✔ decrease
the value of r.
Answer:
✔ a strong positive
✔ weaken
✔ decrease
ED2021
Answer:
The scatterplot including only the blue data points shows
✔ a strong positive
association. Including the orange data point at (86, 0.4) would
✔ weaken
the correlation and
✔ decrease
the value of r.
Step-by-step explanation:
the line parallel to 2x – 3y = 6 and containing (2,6)
what is the equation of the line ?
First, write out the equation in slope intercept form.
-3y= -2x+6
y= 2/3x -2
The slope of the equation is 2/3, m.
Substitute the slope and coordinate into y=mx+b. Since it’s parallel, the slope remains the same.
6= 2/3(2)+b
6= 4/3+b
14/3=b
y= 2/3x + 14/3
At snack time, Ms. Rivera passes out 24 cookies to her class. She also passes out 1 glass of lemonade to each student. This equation correctly represents the total number of items distributed, where a is the number of students in the class.
a(2+1)=36
What is the value of a?
=======================================================
Explanation:
Let's solve the given equation for the variable 'a'
a(2+1) = 36
a*(3) = 36
3a = 36
a = 36/3
a = 12
There are 12 students in the class. This must mean there are 12 lemonades, because each person gets 1 lemonade.
Since there are 24 cookies, each student gets 24/12 = 2 cookies
Since each student gets 2 cookies and 1 lemonade, this is where the "2+1" comes from in the original equation. Each student gets 3 items total, which explains the notation 3a.
The value of 'a' from the given expression would be 13.
Given that;
At snack time, Ms. Rivera passes out 24 cookies to her class. She also passes out 1 glass of lemonade to each student.
Here, the equation is,
a(2+1)=36
Solve for a;
a × 3 = 36
3a = 36
Divide both sides by 3;
a = 36/3
a = 13
Thus, the value of a is 13.
Learn more about the equation visit:
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