QNT 561

1) Question: Hypothesis Testing:  Suppose you that Sprint claim that their cell phone battery last more than 3.5 hours of use. You conduct a sample of 45 batteries and found they lasted 3.72 hours. Assume the standard deviation is 0.7 hours. Test Sprint's claim at 0.10 significance level by comparing the calculated z-score to the critical z-score.

2) Question: Hypothesis Testing:  Suppose a high school claim that the average SAT mat score for graduating class has exceeded 500.  A sample test of 70 students had 530 SAT mat score with standard deviation of 125.  Test the claim at the 0.05 significance level by comparing the calculated z-score to the critical score.

3) Question: Hypothesis Testing < 30 and Sigma Unknown: Suppose you want to test a claim that houses average less than 90 days in the market. You conducted a sample test of 9 houses that lasted 77.4 on the market with a standard deviation of 29.6 days. Test the claim at the 0.05 significance level by comparing the sample t-score to the critical t-score.