The researcher is interested in how people change on the personality dimension of neuroticism over the years. He administered the neuroticism scale to a random sample of 100 ten-year olds in 1980. He administered the same test to the same group in 1990 when they were 20 years old, then again in 2000 when they were 30 years old, then again in 2010 when they were 40 years old. He plans to administer the test one more time in 2020 when they will be 50 years old. He believes that their neuroticism scores will gradually decrease over the decades. What statistical test should he use to analyze the data? a. Independent Samples t-test b. Chi Square Test of Independence c. One Way ANOVA d. Paired t-test e. Repeated Measures ANOVA

Suppose you are conducting a paired t test to determine whether or not caffeine has an effect on heart rate. You have a sample of 60 participants and they ingest no caffeine each day for a week. At the end of the week, you measure their heart rates and find the mean. Then, the same 60 participants are given 500mg of caffeine every day for a week and again, at the end of the week you measure their heart rates and find the mean. What would the null hypothesis be for this test?

In 2016, the New York Times reported that the average American spent 50 minutes per day on Facebook, as compared to an average of 42 minutes per day reading, exercising, or actually socializing combined. You suspect that this gap has widened over the years, and collect a random sample of 100 people. For 50 of them (again, randomly chosen from your sample), you track their time spent on Facebook; you track the other 50 peoples’ total time spent reading/exercising/socializing. (a) Say the 2016 figures regarding Americans’ time allotments still hold true. If the population standard deviation for minutes using Facebook is 12.5 minutes, and the population standard deviation for minutes spent on reading, exercising, and socializing (referred to from here on as ”Other” activities) is 8 minutes, what are the expected value and the standard error of the difference between the average amount of time spent on Facebook and the average amount of time spent on Other activities computed from a sample…

Two different blood pressure medicines are being compared to determine if the average reduction in blood pressure is the same for each medication. The goal of the study is to determine if the medications differ. Twenty men age 50-60 years old are selected for the study. Ten men are chosen at random to receive the first medication and the other 10 men receive the second medication. Each of the 20 men is monitored for one month to determine the change in blood pressure over that time. Minitab provides the 95% confidence interval for (mu1 - mu2) (2.63, 14.18) a. Interpret this 95% CI. b. What assumptions (be specific) are necessary to construct this CI?