Rob sent an email survey to 2,000 cell phone owners asking about their satisfaction with their current plan. Only 256 people returned the survey and they were predominately 18-24 years old.

Which of the following statements is true?


Rob is ignoring the assumption that all survey participants will want to act independently.


The survey likely has bias because the people who could not answer differ from those who did answer.


Rob included too many people on the survey list, affecting the data collected.


The survey suffers from census issues because only 256 people responded.

Answers

Answer 1

Answer:

option B

everyone has different opinions about different things, since we only recorded the survey of a fourth of the total people, the survey will definitely have bias since the people who dont have to answer survey will not be able to record their opinions


Related Questions

State the correct polar coordinate for the graph shown. It is not the option selected.

Answers

Answer:

Solution : Option D

Step-by-step explanation:

Let's start by listing two cases made possible when r is positive, in ( r, θ ). Remember that in polar coordinates a point is expressed in an ordered pair, where r is the distance from the pole (in this case 9, as it lies on the 9th circle) and theta is the directed angle from the positive x - axis.

( 9, θ ) here theta will be the angle to the terminal side with respect to the positive x - axis. This angle will be 60 degrees more than 90, or 90 + 60 = 150 degrees

( 9, θ ) and here theta will be the remaining degrees, or 360 - 150 = 210 degrees. Right away your solution will be (9, 210°)

Does the function satisfy the hypotheses of the Mean Value Theorem on the given interval? f(x) = 4x2 − 3x + 2, [0, 2]

Answers

Answer:

Yes , it satisfies the hypothesis and  we can conclude that c = 1 is an element of [0,2]

c = 1 ∈ [0,2]

Step-by-step explanation:

Given that:

[tex]f(x) = 4x^2 -3x + 2, [0, 2][/tex]

which is read as the function of x = 4x² - 3x + 2 along the interval [0,2]

Differentiating the function with respect to x is;

f(x) = 8x - 3

Using the Mean value theorem to see if the function satisfies it, we have:

[tex]f'c = \dfrac{f(b)-f(a)}{b-a}[/tex]

[tex]8c -3 = \dfrac{f(2)-f(0)}{2-0}[/tex]

since the polynomial function is differentiated in [0,2]

[tex]8c -3 = \dfrac{(4(2)^2-3(2)+2)-(4(0)^2-3(0)+2)}{2-0}[/tex]

[tex]8c -3 = \dfrac{(4(4)-3(2)+2)-(4(0)-3(0)+2)}{2-0}[/tex]

[tex]8c -3 = \dfrac{(16-6+2)-(0-0+2)}{2-0}[/tex]

[tex]8c -3 = \dfrac{(12)-(2)}{2}[/tex]

[tex]8c -3 = \dfrac{10}{2}[/tex]

8c -3  = 5

8c = 5+3

8c = 8

c = 8/8

c = 1

Therefore, we can conclude that c = 1 is an element of [0,2]

c = 1 ∈ [0,2]

4. Katy has 6 times as many nickels as
Shaun. Shaun has 18 nickels. How many
nickels, n, does Katy have?
n is 6
18.
n=​

Answers

Answer:

[tex]\huge\boxed{n = 108\ nickels}[/tex]

Step-by-step explanation:

Let the nickels with Katy be n

So, the condition is

n = 6 (Shaun nickels)

While Nickels of Shaun = 18 , So

n = 6 (18)

n = 108 nickels

A test-preparation company advertises that its training program raises SAT scores by an average of at least 30 points. A random sample of test-takers who had completed the training showed a mean increase smaller than 30 points.
(a) Write the hypotheses for a left-tailed test of the mean.
(b) Explain the consequences of a Type I error in this context.

Answers

Answer:

(a) Null Hypothesis, [tex]H_0[/tex] : [tex]\mu \geq[/tex] 30 points

    Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] < 30 points

(b) Type I error is that we conclude that test-takers who had completed the training showed a mean increase smaller than 30 points but in actual, the program raises SAT scores by an average of at least 30 points.

Step-by-step explanation:

We are given that a test-preparation company advertises that its training program raises SAT scores by an average of at least 30 points.

A random sample of test-takers who had completed the training showed a mean increase smaller than 30 points.

Let [tex]\mu[/tex] = average SAT score.

(a) So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu \geq[/tex] 30 points

Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] < 30 points

Here, the null hypothesis states that the training program raises SAT scores by an average of at least 30 points.

On the other hand, the alternate hypothesis states that test-takers who had completed the training showed a mean increase smaller than 30 points.

(b) Type I error states the probability of rejecting the null hypothesis given the fact that null hypothesis is true.

According to the question, the Type I error is that we conclude that test-takers who had completed the training showed a mean increase smaller than 30 points but in actual, the program raises SAT scores by an average of at least 30 points.

The consequence of a Type I error is that we conclude the test-takers have low SAT scores but in actual they have an SAT score of at least 30 points.

find the area of square whose side is 2.5 cm

Answers

Answer:

6.25

Step-by-step explanation:

2.5 *2.5=6.25

Answer:

6.25cm^2.

Step-by-step explanation:

To find the area of a square, you multiply the two sides, 2.5✖️2.5.

This gives the area of 6.25cm^2.

Hope this helped!

Have a nice day:)

How many times does the digit 9 appear in the list of all integers from 1 to 500? (The number $ 99 $, for example, is counted twice, because $9$ appears two times in it.)

Answers

Answer:

95 times digit 9 appears in all integers from 1 to 500.

Step-by-step explanation:

No. of 9 from

1-9: 1 time

10-19:  1 time

20-29: 1 time

30-39: 1 time

40-49: 1 time

50-59: 1 time

60-69: 1 time

70-79: 1 time

80-89 : 1 time

from 90 to 99

there will be one in 91 to 98

then two 9 in 99

thus, no of 9 from 90 to 99 is 10

Thus, total 9's from 1 to 99 is 9+10 = 19

Thus there 19 9's in 1 to 99

similarly

there will be

19 9's in 100 to 199

19 9's in 200 to 299

19 9's in 300 to 399

19 9's in 400 to 499

Thus, total 9's will be

19 + 19 + 19+ 19 + 19 + 19 = 95

Thus, 95 times digit 9 appears in all integers from 1 to 500.

What is the value of x?

Answers

Answer:

58

Step-by-step explanation:

By the property of intersecting secants outside of a circle, we have:

x° = 1/2( 141° - 25°) = 1/2 * 116° = 58°

Therefore, x = 58

What is the value of b.
C=25
s=9

B=4c-s2

Answers

4(25)-2(9)=100-18=82
b is 82

Answer:

82

Step-by-step explanation:

Plug in the variables into the equation and solve for B but remember your order of operations when solving multiplication/division before addition/subtraction.

B = 4*25-9*2

B = 100-18

B = 82

Problem is attached in a photo

Answers

Answer:

y<(x-2)^2

Step-by-step explanation:

To graph this inequality, we first identify the function.

This is a quadratic function y=x^2

The function is translated horizontally to the right two. (x-2)^2

It is also a dotted line, <.

What is the sign of -456 +456

Answers

Answer:

0

Step-by-step explanation:

-456 +456

( - , + ) = -

so answer is 0

Answer:

0

Step-by-step explanation:

bc i know

If a dog has 2,000,000 toys and he gives 900,000 away. Then gets 2,000 more, also looses 2,000,000. He's sad but then also got 5,000,000,000 more and gives 1,672,293 out. How much does he have now? And how much he gave away. And how much he got.

Answers

Answer:

See below.

Step-by-step explanation:

He does not have enough to loose 2,000,000 at that point, so this whole problem is nonsense.

Find the value of the logarithm. log 122

Answers

Answer:

2.086

Step-by-step explanation:

Log 122 is equal to 2.086

In this diagram, bac~edf. if the area of bac= 6 in.², what is the area of edf? PLZ HELP PLZ PLZ PLZ PLZ

Answers

Answer:

Area of ΔEDF = 2.7 in²

Step-by-step explanation:

It's given in the question,

ΔBAC ~ ΔEDF

In these similar triangles,

Scale factor of the sides = [tex]\frac{\text{Measure of one side of triangle BAC}}{\text{Measure of one side of triangle EDF}}[/tex]

                                        [tex]=\frac{\text{BC}}{\text{EF}}[/tex]

                                        [tex]=\frac{3}{2}[/tex]

Area scale factor = (Scale factor of the sides)²

[tex]\frac{\text{Area of triangle BAC}}{\text{Area of triangle EDF}}=(\frac{3}{2})^2[/tex]

[tex]\frac{6}{\text{Area of triangle EDF}}=(\frac{9}{4})[/tex]

Area of ΔEDF = [tex]\frac{6\times 4}{9}[/tex]

                       = 2.67

                       ≈ 2.7 in²

Therefore, area of the ΔEDF is 2.7 in²                            

What is the median of these figure skating ratings?

6.0 6.0 7.0 7.0 7.0 8.0 9.0

Answers

Answer:

The median would be 7.0.

Step-by-step explanation:

The median of a set of numbers means it is the middle number. since this set has 7 numbers you would need to find the number that is in the middle of the set. This would be the 4th number since it is in the middle. 7.0 is your answer.

which rate can you set 7 miles over 1 hour equal to in order to find the distance traveled in 49 hours at 7 miles per hour

Answers

Answer:

Step-by-step explanation:

time = 49 hours

speed =  7 miles/hour

speed = distance / time

∴ distance = speed × time

= 7 × 49

= 343 miles

The time it takes to install a certain hardware is random. A technician installs this hardware on 64 computers with the average installation time being 42 minutes and the standard deviation of the times being 5 minutes. What is a 90% confidence interval for the popu

Answers

Answer:

[tex]40.97<\mu<43.03[/tex]

Step-by-step explanation:

Th formula for calculating the confidence interval of a population is expressed as shown;

CI = xbar ± Z*S/√n where;

xbar is the mean or average sample

Z is the z-score at 90% confidence

S is the standard deviation

n is the sample size

Given parameters

xbar = 42

Z at 90% CI = 1.645

S = 5

n = 64

Substituting the values into the formula will give;

CI = 42±(1.645*5/√64)

CI = 42±(1.645*5/8)

CI = 42±(1.645*0.625)

CI = 42±1.028125

CI = (42-1.028125, 42+1.028125)

CI = (40.971875, 43.028125)

Hence the 90% confidence interval for the population is approximately (40.97, 43.03) i.e [tex]40.97<\mu<43.03[/tex]

Credit card companies lose money on cardholders who fail to pay their minimum payments. They use a variety of methods to encourage their delinquent cardholders to pay their credit card balances, such as letters, phone calls and eventually the hiring of a collection agency. To justify the cost of using the collection agency, the agency must collect an average of at least $200 per customer. After a trial period during which the agency attempted to collect from a random sample of 100 delinquent cardholders, the 90% confidence interval on the mean collected amount was reported as ($190.25, $250.75). Given this, what recommendation(s) would you make to the credit card company about using the collection agency

Answers

Answer with  explanation:

A x% confidence interval interprets that a person can be x% confident thatthe true mean lies in it.

Here, Credit card companies is using the collection agency to justify the cost of , the agency must collect an average of at least $200 per customer.

i.e. [tex]H_0:\mu \geq200,\ \ \ H_a:\mu<200[/tex]

The 90% confidence interval on the mean collected amount was reported as ($190.25, $250.75) .

I recommend that we can be 90% sure that the true mean collected amount  lies in ($190.25, $250.75).

Also, $200 lies in it such that it is more far from $250.75 than $190.25, that means there are large chances of having an average is at least $200 per customer.

PLS HELP !!

Define two terms, each containing the variables x and y, with exponents on each. (For Example : 10x³y–⁵)Find the quotient of the two terms. Explain step-by-step how you found the quotient

Answers

Answer:

Step-by-step explanation:

Two such terms are 7x^3*y^9 and -3x*y^5

Their quotient is

7x^3*y^9

--------------

 -3x*y^5

This can be simplified as follows:

The numerical coefficients become -7/3.

x^3/x = x^3*x^1 = x^(3 - 1) = x^2 (we subtract the exponent of x in the denominator from the exponent of x in the numerator).

Next, y^9*y^5 = y^4.

The quotient in final reduced form is then (-7/3)x^2*y^4

What is the equation of the following line? Be sure to scroll down first to see all answer options.



A.
y = - 1/2x

B.
y = 1/2x

C.
y = 2x

D.
y = -6x

E.
y = 6x

F.
y = 3x

Answers

Answer:

y=-6x

Step-by-step explanation:

Quick! Andrew has to play 15 games in a chess tournament. At some point during the tournament he has won half of the games he has played, he has lost one-third of the games he has played and two have ended in a draw. How many games has Andrew still to play?

Answers

[tex]x[/tex] - the number of the games he played

[tex]\dfrac{x}{2}[/tex] - the number of the games he won

[tex]\dfrac{x}{3}[/tex] - the number of the games he lost

[tex]x=\dfrac{x}{2}+\dfrac{x}{3}+2\Big|\cdot6\\6x=3x+2x+12\\x=12[/tex]

[tex]15-12=3[/tex]

so, he has still 3 games to play

To the nearest square inch, what is the surface area of the square pyramid shown in the image? A. 175 in.^2 B. 200 in.^2 C. 400 in.^2 D. 700 in.^2 Please show ALL work! :D

Answers

Answer: C. 400  in^2

Step-by-step explanation:

First find the surface area or the area of the base which is in the shape of  a square and has a side length of 10 in. So square 10 to find the area.

Area of base:  10 * 10 = 100

Next find the area of one of the triangles.

As we could see the triangle has a slant height of 15 in and a base of 10. To find the area of a triangle we multiply the base times the height and multiply it by half.

Area of one triangle.  15 * 10 = 150 * 1/2 = 75  

Since one side of the triangle has a surface area of 75 inches we will multiply it by 4 since there are four triangles to find the total surface area of the four faces.

75 * 4 = 300  

We now know that the the 4 triangles surface area dd up to 300 so we will add it to the area of the base which is 100 to find the whole surface area of the figure.

300 + 100 = 400

Find X using the Angle Sum Theorem

Answers

Answer: x = 125 degree

Explanation:

In a triangle the sum of their angles is 180 degree

Find x:

25 + 30 + x = 180
55 + x = 180
x = 180 - 55
x = 125

Answer:

Step-by-step explanation:

x + 30 + 25 = 180

x + 55 = 180

x = 125

y + 125 = 180

y = 55

one third multiplied by the sum of a and b

Answers

Answer:

1/3(a+b)

hope it helps :>

a+b/3
This is the answer of ur question

What is the sum of the geometric sequence?

Answers

Answer:

B. 259

Step-by-step explanation:

6^(i - 1) for i = 1 to 4

sum = 6^(1 - 1) + 6^(2 - 1) + 6^(3 - 1) + 6^(4 - 1) =

= 6^0 + 6^1 + 6^2 + 6^3

= 1 + 6 + 36 + 216

= 259

Answer: B. 259

_______% of 44 = 22​

Answers

Answer:

50%

Step-by-step explanation:

22 is half of 44.

So, this means 50% of 44 is 22.

Determine whether the sequence converges or diverges. If it converges, find the limit. (If an answer does not exist, enter DNE.)
an = (−3^n)/(4n!)

Answers

Answer:

[tex]a_{i} = \frac{(-3)^{i}}{4\cdot i!}[/tex] converges.

Step-by-step explanation:

The convergence analysis of this sequence is done by Ratio Test. That is to say:

[tex]r = \frac{a_{n+1}}{a_{n}}[/tex], where sequence converges if and only if [tex]|r| < 1[/tex].

Let be [tex]a_{i} = \frac{(-3)^{i}}{4\cdot i!}[/tex], the ratio for the expression is:

[tex]r =-\frac{3}{n+1}[/tex]

[tex]|r| = \frac{3}{n+1}[/tex]

Inasmuch [tex]n[/tex] becomes bigger, then [tex]r \longrightarrow 0[/tex]. Hence, [tex]a_{i} = \frac{(-3)^{i}}{4\cdot i!}[/tex] converges.

Please help. I’ll mark you as brainliest if correct!

Answers

Answer:

The system is dependent:

x=-3t-7

y=-5t-15

z=t

Step-by-step explanation:

I chose to use a matrix to solve this system of equations. Once put into matrix form, you need to row reduce the system into its simplest form (Row Reduced Echelon form). Doing this, we find that the system is dependent on the z variable. And following usual procedures, we let z equal some other letter; which is t in this case. Then we isolate each variable to get the answer.

Check the attachment for the work.

[The arrows indicate a row swap and the parenthesis indicates addition if a constant multiple of one row to another]

Two friends compete with each other and five other, equally good, violinists for first and second chair in an orchestra, in a blind competition What is the probability that the two friends end up as first and second chair together?

Answers

Answer: 0.0476

Step-by-step explanation:

Given : Two friends and 5 other people compete with each other for first and second chair in an orchestra.

Total people in this competition= 2+5=7

By permutation , Number of ways to arrange 7 people= 7!

Also, number of ways for two friends end up as first and second chair together= 2 × 5!   [ 2 ways to arrange friends on first and second chair and 5! ways to arrange others]

I.e. Required probability = [tex]\dfrac{2\times5!}{7!}[/tex]

[tex]=\dfrac{2!\times5!}{7\times6\times5!}\\\\=\dfrac{1}{7\times3}\\\\=\dfrac{1}{21}\\\\=0.0476[/tex]

Hence, the probability that the two friends end up as first and second chair together = 0.0476

A computer password is required to be 7 characters long. How many passwords are possible if the password requires 3 letter(s) followed by 4 digits (numbers 0-9), where no repetition of any letter or digit is allowed

Answers

Answer:

[tex]78,\!624,\!000[/tex].

Step-by-step explanation:

Note the requirements:

Repetition of letter or digit is not allowed.The order of the letters and digits matters.

Because of that, permutation would be the most suitable way to count the number of possibilities.

There are [tex]\displaystyle P(26,\, 3) = \frac{26!}{(26 - 3)!} = 26 \times 25 \times 24 = 15,\!600[/tex] ways to arrange three out of [tex]26[/tex] distinct letters (without replacement.)

Similarly, there are [tex]\displaystyle P(10,\, 4) = \frac{10!}{(10 - 4)!} = 10 \times 9 \times 8 \times 7= 5,\!040[/tex] ways to arrange four out of [tex]10[/tex] distinct numbers (also without replacement.)

Therefore, there are [tex]15,\!600[/tex] possibilities for the three-letter section of this password, and [tex]5,\!040[/tex] possibilities for the four-digit section. What if these two parts are combined?

Consider: if the first three letters of the password were fixed, then there would be [tex]5,\!040[/tex] possibilities. However, if any of the first three letters was changed, the result would be another [tex]5,\!040\![/tex] possibilities, all of which are different from the previous [tex]5,\!040\!\![/tex] possibilities. These two three-letter sections along will give [tex]2 \times 5,\!400[/tex] possibilities. Since there are [tex]15,\!600[/tex] three-letter sections like that, there would be [tex]15,\!600 \times 5,\!400 = 78,\!624,\!000[/tex] possible passwords in total. That gives the number of possible passwords that satisfy these requirements.

At a store An orange costs 18 cents A pineapple costs 27 cents An apple costs 15 cents How much does a strawberry cost??​

Answers

Answer:

A strawberry cost 30 cents

Step-by-step explanation:

Given:

Orange= 18 cents

Pineapple = 27 cents

Apple = 15 cents

Strawberry = ?

From the given:

Orange has 6 letters multiplied by 3

=6 * 3

=18 cents

Pineapple has 9 letters multiplied by 3

=9 * 3

=27 cents

Apple has 5 letters multiplied by 3

= 5 * 3

= 15 cents

Therefore, cost of the strawberry=

Strawberry has 10 letters. Multiply the 10 letters by 3

That is,

10 × 3

= 30 cents

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