Project 4 Hypothesis Testing
Determine which hypothesis test needs to be run and show the 6 steps to test each claim. There are 5 different tests that we learned with different test statistic formulas for each one: one-sample test of proportions, one-sample test of means, two-sample test of proportions, two-sample test of means, and correlation.
1. In a USA Today poll of 737 respondents, 678 said they do not read unfamiliar emails or instant-message links. Use a .05 significance to test the claim that more than 75% do not open unfamiliar emails or instant-message links. Show work and all 6 steps.
2. In a 24-month study, the rainfall amounts in each month in Oklahoma City were recorded. It was found that the mean rainfall amount is 1.5 in. with a standard deviation of 0.2 in. Test the claim that OKC gets less than .8 in. per month. Show work and all 6 steps.
3. Does stress affect the recall ability of police eyewitnesses? This issue was studied in an experiment that tested eyewitness memory a week after a nonstressful interrogation and a stressful interrogation of an uncooperative and belligerent suspect. The numbers of details recalled by the witnesses were recorded. Summary statistics are listed below. Test the claim that “stress decreases the amount recalled”. Show all 6 steps. Nonstress: n=40, =53.3, s=11.6 Stress: n=40, =45.3, s=13.2
4. Carpal tunnel syndrome is a common wrist complaint resulting from a compressed nerve, and it is often caused by repetitive wrist movements. In a trial of 73 patients treated with surgery and evaluated one year later, 67 were found to have successful treatments. Among 83 patients treated with splints and evaluated one year later, 60 were found to be successful treatments. A journal article claims that carpal tunnel surgery resulted in better outcomes than those treated with splints. Test this claim at the .05 level.
5. Listed below are numbers of student enrollments (in thousands) at different universities and the numbers of burglaries reported at those large colleges. Is there sufficient evidence to conclude that there is a correlation between enrollment and burglaries? Show all 6 steps.
enrollment 32 31 53 28 27 36 42 30 34 46 burglaries 103 103 86 57 32 131 157 20 27 161
