Question

1. Suppose that you wish to test a claim about a population mean. Which distribution should be used given that the sample is a simple random sample, σ is not known, n = 15 and the population is normally distributed?
   1. The z-distribution
   2. The t-distribution
   3. The Chi-Square Distribution
   4. The F-distribution
2. A hypothesis in statistics is a claim or a statement about a

1. sample statistic
2. population parameter
3. legitimate inheritance
4. weather conditions

3. A market researcher selects every 40^th student from a group of 500 students. What method is being used to select the sample?
   1. cluster sampling
   2. stratified random sampling
   3. volunteer sampling
   4. systematic sampling
4. Type II error is

1. the mistake of rejecting the null hypothesis when it is false.
2. the mistake of failing to reject the null hypothesis when it is false.
3. the mistake of rejecting the null hypothesis when it is true.
4. the mistake of failing to reject the null hypothesis when it is true.

5. Which of the following values could not represent a correlation coefficient?
   1. 1.045
   2. 0
   3. 0.928
   4. - 1
6. Which of the following would be an appropriate null hypothesis?

a. The mean of a population is equal to 100

b. The mean of a sample is equal to 100.

c. The mean of a population is greater than 100.

d. The mean of a sample is less than 100.

7. The width of a confidence interval estimate of the population mean increases when the:

a.    level of confidence increases.

b.    sample size decreases.

c.    value of the population standard deviation increases.

d.    all of these choices are true.

8. Assume n₁ = 382 and x₁ = 72, n₂ = 183 and x₂ = 69, calculate the pooled sample proportion p .

1. 0.250
2. 0.125
3. 0.175
4. 0.225

9. The effectiveness of a headache medicine is tested by measuring the intensity of a headache in patients before and after drug treatment. The data consists of before and after measurements for each patient. Determine whether the samples are independent or dependent or neither.

1. Dependent
2. Independent
3. Neither
4. Not enough information

10.    In a perfectly symmetric bell shaped "normal" distribution:

a.   The mean equals the median.           

b.   The mean equals the mode.

c.   The median equals the mode.

d.   All of these choices are true.

Answer 1

Solution:

Question 1

The correct option is B

Explanation:

For any given sample is a simple random sample if the σ is not known and n > 30 , we always use the T-Distribution