1.2 Data, Sampling, and Variation in Data and Sampling — Introductory Statistics 2e

1.2 Exercise 3

You go to the supermarket and purchase three cans of soup (19 ounces tomato bisque, 14.1 ounces lentil, and 19 ounces Italian wedding), two packages of nuts (walnuts and peanuts), four different kinds of vegetable (broccoli, cauliflower, spinach, and carrots), and two desserts (16 ounces pistachio ice cream and 32 ounces chocolate chip cookies).

Name data sets that are quantitative discrete, quant…

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1.2 Exercise 4

The following list of materials was purchased by a purchase manager in a company:

Two types of nails (2 kg box nails, 3 kg roofing nails)
One type of oil (4 L machine oil)
Four types of screws (3 kg wood screws, 5 kg machine screws, 1 kg set screws, 2 kg socket screws)

Name data sets that are quantitative discrete, quantitative continuous, and qualitative.

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1.2 Exercise 6

Work collaboratively to determine the correct data type (quantitative or qualitative). Indicate whether quantitative data are continuous or discrete. Hint: Data that are discrete often start with the words "the number of."

the number of pairs of shoes you own
the type of car you drive
the distance it is from your home to the nearest grocery store
the number of classes you take per school year.
the…

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1.2 Exercise 10

A study is done to determine the average tuition that San Jose State undergraduate students pay per semester. Each student in the following samples is asked how much tuition they paid for the Fall semester. What is the type of sampling in each case?

A sample of 100 undergraduate San Jose State students is taken by organizing the students’ names by classification (first-year, sophomore, junior, or s…

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1.2 Exercise 12

Determine the type of sampling used (simple random, stratified, systematic, cluster, or convenience).

A soccer coach selects six players from a group of boys aged eight to ten, seven players from a group of boys aged 11 to 12, and three players from a group of boys aged 13 to 14 to form a recreational soccer team.
A pollster interviews all human resource personnel in five different high tech comp…

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1.2 Exercise 14

It is unlikely that any student is in both samples.

a. Do you think that either of these samples is representative of (or is characteristic of) the entire 10,000 part-time student population?

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1.2 Exercise 15

It is unlikely that any student is in both samples.

b. Since these samples are not representative of the entire population, is it wise to use the results to describe the entire population?

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1.2 Exercise 16

$180
$50
$150
$85
$260
$75
$180
$200
$200
$150

c. Is the sample biased?

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1.2 Exercise 19

Use the following information to answer the next four exercises: A study was done to determine the age, number of times per week, and the duration (amount of time) of residents using a local park in San Antonio, Texas. The first house in the neighborhood around the park was selected randomly, and then the resident of every eighth house in the neighborhood around the park was interviewed.

The sampl…

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1.2 Exercise 21

Use the following information to answer the next four exercises: A study was done to determine the age, number of times per week, and the duration (amount of time) of residents using a local park in San Antonio, Texas. The first house in the neighborhood around the park was selected randomly, and then the resident of every eighth house in the neighborhood around the park was interviewed.

The color…

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1.2 Exercise 23

Use the following information to answer the next four exercises: A study was done to determine the age, number of times per week, and the duration (amount of time) of residents using a local park in San Antonio, Texas. The first house in the neighborhood around the park was selected randomly, and then the resident of every eighth house in the neighborhood around the park was interviewed.

the table…

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1.2 Exercise 25

For the following four exercises, determine the type of sampling used (simple random, stratified, systematic, cluster, or convenience).

A market researcher polls every tenth person who walks into a store.

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1.2 Exercise 27

For the following four exercises, determine the type of sampling used (simple random, stratified, systematic, cluster, or convenience).

A computer generates 100 random numbers, and 100 people whose names correspond with the numbers on the list are chosen.

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1.2 Exercise 29

Researcher B: 3; 14; 11; 5; 16; 17; 28; 41; 31; 18; 14; 14; 26; 25; 21; 22; 31; 2; 35; 44; 23; 21; 21; 16; 12; 18; 41; 22; 16; 25; 33; 34; 29; 13; 18; 24; 23; 42; 33; 29

Determine what the key term data refers to in the above example for Researcher A.

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1.2 Exercise 31

Researcher B: 3; 14; 11; 5; 16; 17; 28; 41; 31; 18; 14; 14; 26; 25; 21; 22; 31; 2; 35; 44; 23; 21; 21; 16; 12; 18; 41; 22; 16; 25; 33; 34; 29; 13; 18; 24; 23; 42; 33; 29

Can you tell if one researcher is correct and the other one is incorrect? Why?

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1.2 Exercise 33

Researcher B: 3; 14; 11; 5; 16; 17; 28; 41; 31; 18; 14; 14; 26; 25; 21; 22; 31; 2; 35; 44; 23; 21; 21; 16; 12; 18; 41; 22; 16; 25; 33; 34; 29; 13; 18; 24; 23; 42; 33; 29

Suggest at least two methods the researchers might use to gather random data.

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1.2 Exercise 35

Researcher B: 3; 14; 11; 5; 16; 17; 28; 41; 31; 18; 14; 14; 26; 25; 21; 22; 31; 2; 35; 44; 23; 21; 21; 16; 12; 18; 41; 22; 16; 25; 33; 34; 29; 13; 18; 24; 23; 42; 33; 29

Suppose that the second researcher conducted his survey by choosing 40 patients he knew. What sampling method would that researcher have used? What concerns would you have about this data set, based upon the data collection method…

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1.2 Exercise 37

Would the sample size be large enough if the population is the students in the school?

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1.2 Exercise 39

Researcher A concludes that most students play video games between four and six hours each week. Researcher B concludes that most students play video games between two and four hours each week. Who is correct?

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1.2 Exercise 41

Given what you know, which study is correct?

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1.2 Exercise 43

Both groups that performed the study concluded that the software works. Is this accurate?

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1.2 Exercise 45

Patients who used the software were also a part of an exercise program whereas patients who did not use the software were not. Does this change the validity of the conclusions from the exercise?

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1.2 Exercise 47

Is a sample of 500 volunteers a reliable measure for a population of 2,500?

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