Question1

Suppose that there are 3,500 students in State College U and the mean credit hours completed is 28 and the standard deviation is 3. You randomly select 200 students. Based on this sample, the mean credit hours completed is 21 and the standard deviation is 2. In this example, the value of is:

1. 28
2. 3500
3. 21
4. 3

Question2

Suppose that there are 1,000 students in College U and the mean credit hours completed is 30 and the standard deviation is 5. You randomly select 100 students. Based on this sample, the mean credit hours completed is 28 and the standard deviation is 7. In this example, the value of is:

1. 7
2. 100
3. 1000
4. 30
5. 28
6. 5

Question 3

Assume that a random variable X has a mean of 100 and a standard deviation of 10. If you take a large sample from this population, based on the Central Limit Theorem, what is the shape of the sampling distribution of means?

1. Unimodal
2. Uniform
3. Normal
4. Bimodal

Question 4

Assume that a random variable X has a mean of 150 and a standard deviation of 12. If you take a large sample from this population, based on the Central Limit Theorem, what is the shape of the sampling distribution of means?

1. Abnormal
2. Gaussian
3. Normal
4. Bimodal

Question 5

An unknown distribution has a mean of 100 and a standard deviation of 14. Sample of size n = 49 are drawn randomly from the population. What is the thestandard error of the meanfor this sample?

1. 0.2857
2. 2
3. 0.99999
4. 1.4

Question 6

An unknown distribution has a mean of 210 and a standard deviation of 45. Sample of size n = 75 are drawn randomly from the population. Using the z-table or a technology (e.g. calculator), find the probability that the sample mean is greater than 212.

1. 0.3502
2. 0.99999
3. 0.5009
4. 0.2584

Question 7

If the point estimate of a population mean is 10 and the margin of error is 1, the confidence interval is:

1. (9,11)
2. (8.5,11.5)
3. (9.5,10.5)
4. (8,12)

Question 8

Student t-Distribution is used when:

1. The variable is categorical
2. The population standard deviation is unknown
3. Standard normal distribution table (z-table) is not available
4. The population size is small