There are 16 questions on this quiz. You will see a small group of

questions at a time.

Consider the following study: Marketing researchers Dominique and Huong

wanted to know the following: "What percent of customers wear rain jackets

at Seattle Food Store each day?" In an attempt to answer that question,

Dominique and Huong designed a study. They called the store manager and

arranged to collect data for 20 days. The researchers collected data for 4

hours each day for 20 days and counted the total number of shoppers who

did and did not wear a rain jacket. The average number of customers per

day who wore a rain jacket during the sample period was 32.

Question 1

Question text

The population in this study was (read each answer and select the best one):

Select one:

a. All shoppers in Seattle.

b. All people who wear rain jackets.

c. All shoppers at the Seattle Food Store.

d. All shoppers at the Seattle Food Store during the study period.

e. The 32 people per day who wore rain jackets to the Seattle Food Store.

Question 2

Question text

The sample in this survey was:

Select one:

a. Dominique and Huong.

b. The people who were observed shopping at the Seattle Food Store during

the study.

c. The people who wear rain jackets.

d. The four hours per day that were studied.

e. The 32 people per day who wore rain jackets to the Seattle Food Store.

Question 3

Question text

How would you describe the possibility that the sample was biased (read all

answers and select the best one):

Select one:

a. There is no bias because the sample was large.

b. There is no bias because the multiple days were sampled.

c. There could be bias because the selected days might not be representative

of all the days (such as changing weather).

d. Not enough information to determine the answer.

Use this information for the next four questions: Researchers wanted to know

about a standardized test that was used across the country. To get an

estimate of the answer, they collected data from two classrooms of students

who completed the test.

Scores from Classroom A:

8, 6, 9, 9, 8, 7, 8, 9, 10, 8, 10, 5, 4, 10, 9, 9

Scores from Classroom B:

9, 8, 7, 8, 9, 10, 9, 10, 7, 8, 10, 9, 9, 4, 6, 3

Question 4

Question text

The set of all scores on the standardized test across the country is:

Select one:

a. a statistic

b. a parameter

c. the sample

d. the population

Question 5

When all the scores for the two classrooms are added and divided by the

number of observations, the resulting value is a:

Select one:

a. a statistic

b. a parameter

c. the sample

d. the population

Question 6

Not yet answered

Marked out of 1.00

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Question text

What is the mean score in Group A?

Select one:

a. 8.4375

b. 8.3125

c. 8.0625

d. 8.375

e. 8.4375 / sqrt(n)

Question 7

Load data for Group B into an R object called B, then run this command:

barplot(table(B))

What does the bar on the right represent?

Select one:

a. Nine students received a score of 5 on the quiz.

b. One student received a score of 6 on the quiz.

c. Three students received a score of 7 on the quiz.

d. Four students received a score of 9 on the quiz.

e. Three students received a score of 10 on the quiz.

Eighty adults with gum disease were asked the number of times per day they

flossed. The (incomplete) results are shown below:

# per day Freq. Rel. Freq Cum. Rel. Freq

0 15 .1875

1 21 .2625

2 18 .2250

3 .7875

4 9 .9000

5 8 1.000

Fill in the blanks in the table and answer the next two question:

Question 8

The count of people who flossed three times per day is:

Select one:

a. 11

b. 18

c. 12

d. 9

e. can not be determined

Question 9

The cumulative relative frequency of those who flossed 0 to 2 times per day

is:

Select one:

a. .2250

b. .7875

c. .6750

d. .1875

e. 0.000

Use this information for the next six questions:

category <- c('a', 'g', 'd', 'a', 'd', 'g', 'g', 'd')

speed <- c(60, 83.3, 71, 64.4, 75, 90, 87, 73)

Question 10

The data type of the category object is:

Select one:

a. numeric

b. factor

c. complex

d. mixed

Question 11

The data type of the speed object is:

Select one:

a. numeric

b. factor

c. complex

d. mixed

Question 12

What is the mean of the category object?

Select one:

a. 'a'

b. 'd'

c. 'g'

d. between 'd' and 'g'

e. none of the above

Question 13

What is the mean of speed (rounded to 1 decimal place)?

Select one:

a. 75.5

b. 90.0

c. 60.0

d. 74.0

Question 14

What is the sample standard deviation of the speed data (rounded to 1

decimal place)?

Select one:

a. 113.4

b. 74.5

c. 10.6

d. 90.0

Question 15

What is the minimum value of the speed data:

Select one:

a. 15.1

b. 60.0

c. 74.0

d. 14.9

e. 30.0

Some researchers collected data on the number of pairs of shoes that

students own. Five students owned seven pairs, two students owned no

pairs, and various students owned between one and five pairs of shoes. See

the data in the frequency table:

Shoes owned 0 1 2 3 4 5 7

Frequency 2 4 20 8 6 4 5

Question 16

What is the mean of the number of pairs of shoes that the students owned?

Select one:

a. 3.0

b. 3.1

c. 2.6

d. 2.9

e. 2.2