Special Directions --For each exercise, students must:

1. Write down the null and alternative hypotheses as a complete sentence
2. Using symbolic notation.
3. Write down calculator input and output values.
4. Write a conclusion as a complete sentence.

Exercises:

1 Red Blood Cell Count

A simple random sample of 50 adults is obtained, and each person's red blood cell count (in cells per microliter) is measured. The sample mean is 5.23 and the standard deviation of all red blood cell counts is 0.54.Use a 1% significance level to test the claim that the sample is from a population with a mean less than 5.4.What do the results suggest about the sample group?

2 Is the Diet Practical?

When 40 people used the Weight Watchers diet for one year, their mean weight loss was 3 lbs.Assume that the standard deviation of all such weight changes is 4.9 lbs and use a 1% significance level to test the claim that the mean weight loss is greater than 0. Based on the results, does the diet appear to be effective?

3 FICO Credit Scores

A simple random sample of FICO credit rating scores is obtained, and the scores are listed below.As of this writing (2008), the mean FICO score was reported as 678. Assuming the standard deviation of all FICO scores is known to be 58.3, use a 5% significance level to test the claim that these samples come from the same population.

SAMPLE (n=12): 714, 751, 664, 789, 818, 779, 698, 836, 753, 834, 693, and 802