Here is a quiz tht I have to have done by tomorrow, the problem is is that I do not understand any of this so if anyone could help, I would appreciate it more than you would ever know.
Here is the quiz:
Please place all your work in one Excel file and place it in the Assignments folder.
T F 1. If 40 samples of size 21 were selected from a population of 22,493, we would expect the mean of the sample means and the population mean to be close but not exactly equal.
T F 2. If the sample size keeps getting larger and larger and finally equals the size of the population, there would be no error in predicting the population mean because the sample size and the size of the population would be the same.
3. As the size of the sample increases, what happens to the shape of the sampling means?
A. Cannot be predicted in advance
B. Approaches a normal distribution
C. Positively skewed
D. Negatively skewed
T F 4. The level of significance is the risk we assume of rejecting the null hypothesis when it is actually true.
T F 5. There is no one level of significance that is applied to all studies involving sampling.
T F 6. If we do not reject the null hypothesis based on sample evidence, we have proven beyond doubt that the null hypothesis is true.
7. What value does the null hypothesis make a claim about?
A. Population parameter
B. Sample statistic
C. Sample mean
D. Type II error
T F 7. The Student t distribution has a greater spread than does the z distribution. As a result, the critical values of t for a given level of significance are larger in magnitude than the corresponding z critical values.
T F 8. Since there is more variability in sample means computed from smaller samples, we have more confidence in the resulting estimates and are less apt to reject null hypothesis.
9. From RES 341 – review problem: A survey of 600 randomly selected people reveals that 384 of them think that the President of the United States is doing a good job regarding domestic issues.
a. What is the point estimate and what does this mean?
b. What is the 95% confidence interval to estimate the true proportion of people who think the president is doing a good job?
c. Interpret the interval you developed above.
10. The mean length of a small counterbalance bar is 43 millimeters. The production supervisor is concerned that the adjustments of the machine producing the bars have changed. He asks the Engineering Department to investigate. Engineering selects a random sample of 12 bars and measures each. The results are reported below in millimeters:
42 39 42 45 43 40 39 41 40 42 43 42
Is it reasonable to conclude that there has been a change in the mean length of the bars? Use the .02 level of significance. Show all 5 steps – interpret your conclusion!