Test Content

1. 
   
   An upper-level sociology class has 120 registered students: 34 seniors, 57 juniors, 22 sophomores, and 7 freshmen. Imagine that you choose one random student from the classroom (perhaps by using a random number table).

2. 
   
   Question 1

   2.5 PointsWhat is the probability that the student will be a junior?

   1. 0.475
   2. 0.57
   3. 0.183
   4. 0.283

3. 
   
   Question 2

   2.5 PointsWhat is the probability that the student will be a freshman?

   1. 0.475
   2. 0.058
   3. 0.283
   4. 0.183

4. 
   
   Question 3

   2.5 PointsIf you are asked to select a proportionate stratified sample of size 30 from the classroom, stratified by class level (senior, junior, etc.), how many students from each group will there be in the sample?

   1. About 1 Freshmen, about 4 Sophomores, about 13 Juniors, about 9 Seniors
   2. About 3 Freshmen, about 7 Sophomores, about 15 Juniors, about 8 Seniors
   3. About 2 Freshmen, about 5 Sophomores, about 14 Juniors, about 8 Seniors
   4. About 3 Freshmen, about 7 Sophomores, about 15 Juniors, about 10 Seniors

5. 
   
   Question 4

   2.5 PointsIf you select a disproportionate sample of size 20 from the classroom, with equal numbers of students from each class level in the sample, how many freshmen will be in the sample?

   1. 5
   2. 7
   3. 9
   4. 6

6. 
   
   Question 5

   2.5 PointsWhen taking a random sample from a very large population, how does the standard error of the mean change when the sample size is increased from 100 to 1,600?

   1. Smaller by a factor of 2
   2. Larger by a factor of 2
   3. Smaller by a factor of 4
   4. Larger by a factor of 4

7. 
   
   Question 6

   2.5 PointsWhen taking a random sample from a very large population, how does the standard error of the mean change when the sample size is decreased from 300 to 150?

   1. Decreases by 1.41
   2. Increases by 1.41
   3. Decreases by 0.71
   4. Increases by 0.71

8. 
   
   Question 7

   2.5 PointsWhen taking a random sample from a very large population, how does the standard error of the mean change when the sample size is multiplied by 4?

   1. Decreases by a factor of 4
   2. Increases by a factor of 4
   3. Decreases by a factor of 2
   4. Increases by a factor of 2

9. 
   
   The following information presents the number of parolees (per 100,000 people) for 12 of the most populous states as of July 2015.State, Parolees (per 100,000 People)California, 292Texas, 556New York, 288Florida, 28Illinois, 299Pennsylvania, 1,035Ohio, 193Georgia, 334Michigan, 239North Carolina, 130New Jersey, 214Virginia, 27
   Source: National Institute of Corrections, Correction Statistics by State, 2016

10. 
    
    Question 8

    2.5 PointsAssume that ? = 226.83 for the entire population of 50 states. Calculate and interpret the standard error. (Consider the formula for the standard error. Since we provided the population standard deviation, calculating the standard error requires only minor calculations.) What is the standard error?

    1. 68.45
    2. 62.35
    3. 64.58
    4. 65.48