Weight Watchers claims that people following their program can expect to lose more than 10 lbs in 2 months with a standard deviation of 3 lbs. Researchers selected a group of 50 people participating...

1. Weight Watchers claims that people following their program can expect to lose more than 10 lbs in 2 months with a standard deviation of 3 lbs. Researchers selected a group of 50 people participating in the program and monitored their weight loss over 2 months. The mean weight loss over the 2 months was 10.4 lbs. We want to know if this result supports Weight Watchers’ claim.

1. Draw a normal curve for the sampling distribution of samples of size 50 people. Label the mean and the values for one, two and three standard deviations above and below the mean.


2. Construct a hypothesis test to test the Weight Watchers’ claim using significance level

α=0.05. Be sure to show all your calculations including your test statistic, and your calculated P- value. Be sure to clearly argue your conclusion. Follow these steps:

1. Is this problem about means or proportions?


2. What is the most appropriate test, a two-tailed test, a right-tailed test, or a left-tailed test?

• What is your null hypothesis?

1. What is your alternative hypothesis?


2. What is the value of the test statistic? Please mark the test statistic on your normal curve and shade the area that corresponds to the P-Value, based on the type of test you are using.


3. What is the P-value?

• What is your decision? Do you reject or not reject ?0?


• What is your conclusion? (What does your decision translate to in words? To write your conclusion, please use the conclusion language that was discussed in )

1. Construct a 99% confidence interval for the given