A study is conducted to investigate whether customer satisfaction is greater among computer companies that offer tech support versus those that do not offer tech support. A random sample of 50 customers are selected from among those that purchased computers that offer tech support. A separate random sample of 40 customers are selected from among those that purchased computers that do not offer tech support. The study found that the mean satisfaction rating was significantly greater among customers that purchased computers that offer tech support. Which of the following is the best description of this study?
A) An experiment using a completely randomized design.
B) An experiment using a randomized block design.
C) An experiment using a matched pairs design.
D) An observational study using a simple random sample.
E) An observational study using a stratified sample.

Answers

Answer 1

Answer:

E) An observational study using a stratified sample.

Step-by-step explanation:

This study is not an experiment because the customers were not subjected to any treatment but just observation from those selected. Also, the sampling method used was stratified sampling because we see that random samples were selected independently from two unique populations which are population of those that purchased computers and those that offer tech support.

Therefore the correct option is E.


Related Questions

A ring-shaped region is shown below.
Its Inner radius is 11 cm, and its outer radius is 17 cm.

Find the area of the shaded region. Use 3.14 for pi. Do not round your answer.

Answers

Answer:

527.52 cm²

Step-by-step explanation:

Area of the shaded region = area of the outer circle - area of the inner circle

Area of circle is given as πr²

Radius of inner circle = 11 cm

Area of outer circle = 17 cm

π = 3.14

Thus:

Area of shaded region = 3.14*17² - 3.14*11²

= 907.46 - 379.94

= 527.52 cm²

1. Sprint PCS offers a monthly cellular phone plan for $39.99. It includes 450 anytime minutes and charges $.45 per minute for additional minutes. a. x represents __________________ (2 points) b. f(x) represents ___________________ (2 points) c. Write out your piecewise function, including the domain.

Answers

Answer:

[tex]f(x) = \left \{ {{39.99; 0 \le x \le 450} \atop {0.45x - 162.51; \ x>450}} \right.[/tex]

Step-by-step explanation:

Given

Charges: $39.99 for first 450 minutes

Charges: $0.45 for additional minutes

(a): What is x

x represents the total minutes

(b): What is f(x)

f(x) represents the total monthly cellular charges

(c): The piecewise function

For the first 450 minutes, the function is:

[tex]f(x) = 39.99;\ 0 \le x \le 450[/tex]

For additional minutes.

In (a), the total minutes is x.

So, we have:

Total Charges = Charges for first 450 minutes + Charges for additional minutes * (Minutes after 450 minutes)

[tex]Total\ Charges = 39.99 + 0.45 * (x - 450)[/tex]

[tex]f(x) = 39.99 + 0.45 * (x - 450)[/tex]

Open bracket

[tex]f(x) = 39.99 + 0.45x - 0.45 * 450[/tex]

[tex]f(x) = 39.99 + 0.45x - 202.5[/tex]

Collect Like Terms

[tex]f(x) = 0.45x+39.99 - 202.5[/tex]

[tex]f(x) = 0.45x-162.51[/tex]

The range of the above function is: x > 450.

So, the piecewise function is:

[tex]f(x) = \left \{ {{39.99; 0 \le x \le 450} \atop {0.45x - 162.51; \ x>450}} \right.[/tex]

PLEASE HELP ME WITH BOTH QUESTIONS ASAP!!!!!!!!!

Answers

Answer:

I have #1, answer is 400

Step-by-step explanation:

80% of 500 is 400

Answer:

First one is 400

Step-by-step explanation:

In a study, Phoenix Marketing International identified Bridgeport, Connecticut; San Jose, California; Washington, DC; and Lexington Park, Maryland, as the four U.S. cities with the highest percentage of millionaires (Kiplinger website). Consider a sample of data that show the following number of millionaires for samples of individuals from each of the four cities. City Bridgeport,San Jose,Washington,Lexington Park, MillionaireCTCAD.C.MD Yes45333634 No455267364366 a. What is the estimate of the percentage of millionaires in each of these cities (to 1 decimal)

Answers

Answer:

The estimate of the percentage of millionaires in each of these cities:

                          Bridgeport      San Jose    Washington    Lexington Park

                                CT                 CA               D.C.                MD

Percentage of

Millionaires             9%                 12%              9%                 8.3%

Step-by-step explanation:

Data and Calculations:                            City

                            Bridgeport,     San Jose,   Washington,   Lexington Park,

Millionaire                   CT                 CA              D.C.                 MD

Yes                             45                  36               36                    33

No                              455               264             364                 367

Sample                      500               300             400                 400

Percentage of

 Millionaires            45/500         36/300         36/400           33/400

=                               0.09               0.12             0.09            0.0825

=                                 9%                 12%              9%               8.3%

Using the percentage concept, it is found that the estimate of the percentage of millionaires in these cities is of 9.25%.

What is a percentage?

The percentage of an amount a over a total amount b is given by a multiplied by 100% and divided by b, that is:

[tex]P = \frac{a}{b} \times 100\%[/tex]

Researching the problem on the internet, it is found that:

A total of 45 + 34 + 37 + 32 + 455 + 266 + 363 + 368 = 1600 people were surveyed, hence b = 1600.Of those, 45 + 34 + 37 + 32 = 148 are millionaires, hence a = 148.

Then:

[tex]P = \frac{148}{1600} \times 100\% = 9.25\%[/tex]

The estimate of the percentage of millionaires in these cities is of 9.25%.

More can be learned about the percentage concept at https://brainly.com/question/10491646

Please help me answer this:)

Will give you brainlst ^

Answers

Okay, got it!

Here's the graph (sorry if it's confusing I'm going to try my best)

             Print   Electronic   Total

Youths    33       28      61

Adults    33       37      70

Total     66        65      131

Hope this helps!

If (X + A) is multiplied times (X + B), the final term of the resulting trinomial will be:

Answers

Answer:

AB

Step-by-step explanation:

Using FOIL (first outer inner last) u can determine that the final term will be produced by multiplying the last terms in each bracket. These are A and B, so the final term of the resulting trinomial is AB.

You can check this by fully expanding (x + A)(x + B):

[tex](x + A)(x + B)\\= x^{2} + Bx + Ax + AB[/tex]

the terms B and A are usually numbers, so Bx and Ax tend to get added together to form a middle term. hope this helps!

Help Please! I'll Give Brainliest!

Answers

Answer:

A

Step-by-step explanation:

the answer is a

Roshanda was curious if students in her class would complete a maze faster if fast-paced music was playing in the background. She randomly assigned each student in her class to one of three groups: fast-paced music, slow-paced music, or no music. She timed each student as they individually completed a maze with their corresponding music (or no music) in the background. Students who worked with the fast-paced music, on average, completed the maze significantly faster than students in the other groups.
Can we conclude that the fast-paced music caused her classmates to finish the maze faster? Why?

(A) Yes, because the study included each student in her class

(B) Yes, because the adults were randomly selected

(C) Yes, because the students were randomly assigned to treatment and control groups

(D) Not necessarily, because the sample size was too small

(E) Not necessarily, because this wasn't an experiment

Answers

Answer: (E) Not necessarily, because this wasn't an experiment

Step-by-step explanation:

As much as the results would suggest that the fast-paced music was responsible for the faster finishing time, this conclusion cannot be authoritatively made because this was not technically an experiment but rather a test to satisfy curiosity.

An experiment is planned and is scientific. It has more stringent requirements that ensure causation that Roshanda did not meet before she engaged in this trial so we cannot say for a fact that her findings are objective.

Answer: C. yes, the students were randomly assigned to treatment and control groups.

Step-by-step explanation:

Suppose that a balanced, six-sided die has been altered so that the faces are 1, 2, 3, 4, 5, and 5. If the die is tossed five times, and the number on the uppermost face is recorded each time, what is the probability that the numbers recorded are 1, 2, 3, 4, and 5 in any order

Answers

Answer:

0.0309

Step-by-step explanation:

Faces on dice ( 1, 2, 3, 4, 5, 5)

Number of outcomes = 6

With 5 repeated twice

P(event A) = Required outcome / Total possible outcomes

Required outcome :

Number of 5's = 2 * distinct faces!

Required outcome = 2 * 5! = 2 * 120 = 240

Total possible outcomes = (number of faces)^distinct Numbers = 6^5 = 7776

Required / total possible = 240 / 7776

= 0.0308641

= 0.0309

Help please! Thank you!!

Answers

Answer:

alternate exterior angle is answer

Answer:

Angle 2 and angle 8 are alternative exterior angles

HELPPPPPPP MEEEEEEEEEEEE

Answers

Answer:

man thats hard

Step-by-step explanation:

The cost of 7 chairs is equal to the cost of 2 tables. If the cost of 6 chairs and 5 tables is Rs.10,575, find the cost of 12 chairs.​

Answers

Answer:

5,400

Step-by-step explanation:

7c = 2t; t = 7c/2

6c +5t = 10575

6c + 5(7c/2) = 10575

6c + 35c/2 = 10575

multiply all through by 2

12c + 35c = 21,150

47c = 21,150

c = 21150/47 = 450

12 chairs = 450 × 12 = 5,400

50 points! Please help fast I need this done ASAP!!! Only answer if you know it. Random answers will be reported!

Answers

3. Is 64 and 4. Is 165 if I’m correct

Verizon Wireless charges
$0.09 for every 5 text
messages sent. How much
is your bill if you send 75
texts?
Make this into a equation

Answers

Answer:

$1.35

Step-by-step explanation:

$0.09/5 = $0.018

75 x $0.018 = $1.35

can i be brainiest...

Russell is purchasing a $175,000 home with a 30-year mortgage. He will put
down $15,000 down payment. Use the table below to find his monthly PMI
payment
Base-To-Loan %
Fixed-Rate Loan
30 yrs. 15 yrs.
ARM 2% + 1 Year Cap
30 yrs.
15 yrs.
95.01% to 97%
0.90% 0.79%
n/a
n/a
90.01% to 95%
0.78% 0.26%
0.92%
0.81%
85.01% to 90%
0.52% 0.23%
0.65% 0.54%
85% and Under
0.32% 0.19%
0.37% 0.26%
O A. $97.50
B. $1170
O c. $1248
O D. $104.00

Answers

104.00

vdybshdbdidbeuvei

heydubeuheisnsndu

While Vivian was visiting her sister in Springfield, she bought a set of bunk beds that was marked down 25% from an original price of $80. If the sales tax in Springfield is 10%, what was the total cost of the set of bunk beds?

Answers

Answer:

66 i think

Step-by-step explanation:

he heights of adults in a certain town have a mean of 65.42 inches with a standard deviation of 2.32 inches. A random sample of 144 adults living in the center of the town was selected and their mean height was found to be 64.82 inches. Find the probability that a sample of this size would have a mean of 64.82 inches or less.

Answers

Answer:

0.001 = 0.1% probability that a sample of this size would have a mean of 64.82 inches or less.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

The heights of adults in a certain town have a mean of 65.42 inches with a standard deviation of 2.32 inches.

This means that [tex]\mu = 65.42, \sigma = 2.32[/tex]

Sample of 144:

This means that [tex]n = 144, s = \frac{2.32}{\sqrt{144}} = 0.1933[/tex]

Find the probability that a sample of this size would have a mean of 64.82 inches or less.

This is the pvalue of Z when X = 64.82. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{64.82 - 65.42}{0.1933}[/tex]

[tex]Z = -3.1[/tex]

[tex]Z = -3.1[/tex] has a pvalue of 0.001

0.001 = 0.1% probability that a sample of this size would have a mean of 64.82 inches or less.

Sam buys 3 different types of fruit in 3-fourths pound baskets. Maria has 1 and 1-fourth pounds fruit.



How many pounds of fruit do they have altogether?

Answers

There are 3.5 pounds of fruit all together

An FBI agent orders a block of ballistics gel. The gel weighs 54 pounds per cubic foot. What is the weight of the block of gel?

Answers

Answer:

22.5 Pounds

Step-by-step explanation:

This is correct because i did it on Big Ideas and got it correct with 22.5.

The graph of r = -3 + 5cos theta is symmetric about the __________.
a.
y-axis only
c.
Origin only
b.
x-axis only
d.
No symmetry

Answers

I believe it it will be the across the y axis

The graph of r = -3 + 5cosθ is symmetric about the option (B) x axis only

What is Symmetry?

In mathematics, symmetry has a more precise definition, and is usually used to refer to an object that is invariant under some transformations; including translation, reflection, rotation or scaling.

Given that,

The graph of r = -3 + 5cosθ is symmetric about what?

When we plot the graph we can say that it is symmetric about x axis only.

Hence, the graph of r = -3 + 5cosθ is symmetric about the option (B) x axis only

Learn more about Symmetry click;

brainly.com/question/16180199

#SPJ3

equations similar to 4x + 12

Answers

Answer:

2(2x+6) is the same problem in a different format.

Step-by-step explanation:

Distribute the 2 to each place which gives you 4x+12

Answere : 4 times (x + 3)

Which equation is represented by the graph below?

Answers

Answer:

y = [tex]\frac{2}{3}x[/tex] + 6

Step-by-step explanation:

Here are the noon temperatures (in degrees Celsius) in a particular Canadian city on Thanksgiving Day for the 10 years from 2002 through 2011: 0, 3, 6, 8, 2, 9, 7, 6, 4, 5. Describe the typical temperature and the amount of variation to a person who has never had a course in statistics. Give three ways of describing the representative temperature and two ways of describing its variation, explaining the differences and how you figured each. (You will learn more if you try to write your own answer first, before reading our answer at the back of the book.)

Answers

Answer:

a) Three ways of describing the representative or typical temperatures are the mean, median, and mode.

The mean = 5.  This is the average temperature.  It is calculated by adding up the varying temperatures each year and dividing by 10.

Median = 5.5.  This is the middle value in the temperature table.  There are two middle numbers (5 and 6) in the dataset.  They are added and divided by two.

Mode = 6.  This is the value that occurs more than other values in the dataset.  The value 6 occurred twice more than other values.

b) The two ways of describing the variation of temperatures are the variance and the standard deviation.

Variance = 7. This is a measure of how spread out a data set is. It is calculated as the average squared deviation of each number from the mean of a dataset.

Standard Deviation = 2.65.  The standard deviation measures the dispersion of a dataset relative to its mean and is calculated as the square root of the variance.

Step-by-step explanation:

a) Data and Calculations:

Noon Temperatures (in degrees Celsius) in a particular Canadian City on Thanksgiving Day:

Year    Degree  Difference     Squared

           Celsius                       Difference

2002        0          -5                     25

2003        3          -2                       4

2004        6           1                        1

2005        8           3                       9

2006        2          -3                       9

2007        9           4                      16

2008        7           2                       4

2009        6           1                        1

2010         4          -1                        1

2011          5          0                       0

Sum       50                                  70

Mean =    5 (50/10)

Variance =                                    7 (70/10)

Standard Deviation = 2.65 (Square root of variance)          

Median =  0, 2, 3, 4, 5, 6, 6, 7, 8, 9 (the values are arranged numerically.)

= (5 + 6)/2 = 5.5

Mode = 6 (occurred twice more than other values)

A research group is interested in gauging perceptions about health club memberships among health club members. Specifically, they wish to determine the percentage of monthly paying members in the United States that believe health club memberships are not too expensive. They listed the members of the health club located nearby in alphabetical order and took every tenth member until they succeeded in contacting 150 members. What kind of sampling method have they used? Choose the correct answer below.
A. Cluster sampling
B. Multistage sampling
C. Stratified random sampling
D. Systematic sampling

Answers

Answer:

D. Systematic sampling

Step-by-step explanation:

Systematic sampling is a type of probability sampling method in which sample members of a large population are selected according to a random starting position and a constant, periodic interval. This interval, called the sample interval, is calculated by dividing the population size by the desired sample size.so correct option is D. Systematic sampling .

I have 15 pounds of flour. How many batches of pizza dough can I make from 1 bag of flour?

Answers

Answer:

with one pound of pizza dough you can make one large pizza or two 10-inch pizzas.

so 15 Large pizzas or 30 10 in pizzas

Step-by-step explanation:

Which fraction is equivalent to (7-3)*3/10^4-10^2
A. 16/25
B. 1/25
C. 8/1125
D. 16/2475

Answers

Answer:

C.8/1125 is the answer......

The symbol used to seperate the tenths and ones is called a?

Answers

The answer you are looking for is called a

Decimal

Have a beautiful day!

If x = -3, find
pls answer

Answers

Answer:

x² - 1 = 8

Step-by-step explanation:

Given the following algebraic expression;

x² - 1

When x = -3

Substituting the value of x, we have;

x² - 1 = (-3)² - 1

x² - 1 = 9 - 1

x² - 1 = 8

Method II.

x² - 1 = (x - 1)(x + 1)

Substituting the value of x, we have;

x² - 1 = (-3 - 1)(-3+ 1)

x² - 1 = -4(-2)

x² - 1 = 8

what is the length of the hypotenuse ​

Answers

The answer is c= 65......

Answer:

65 ft

Step-by-step explanation:

You can find the length of the hypotenuse using the formula a^2+b^2=c^2 where c is the hypotenuse and the other two sides are a and b.

16^2=256

63^2=3969

256+3969=4225

4225=c^2

Get c by itself by taking the square root of both sides.

This leaves you with c=65

~!!!! HELP IM IN 7TH GRADE LEARNING 9TH AND 8TH PLEASE HELP !!!!~
QUESTION~
The graph of g(x) = 4|x| − 3 maps a
person’s path from their house to
school, and their path from school
to a friend’s house. At what point
is the school located?

Answers

Answer:

It would be (0,-3) ^^you can see on the graph

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