1. According to the latest poll, 750 adult respondents believe in global warming. Construct a 95% confidence interval estimate of the proportion of adults who believe in global warming. Round your lower bound and upper bound of the confidence interval to 3 decimal places.
2. Based on the performance of all individuals who took the GRE Verbal Reasoning Exam for the last three academic years, test takers had a mean score of 150 and a standard deviation of 8.5
a. For a sample size of 100, state the standard deviation of the sample mean (standard error of the mean) to 3 decimal places.
b. Find the probability that the sample mean scores is more than 155 (rounded to 3 decimal places)
3. Does an exercise program lower cholesterol? 100 adults were given a weekly exercise program. Cholesterol levels were measured before and after this treatment. the changes in their LDL cholesterol (mg/dL) have a mean of 6 and a standard deviation of 4.
Construct a 90% interval estimate of the mean change in LDL cholesterol after treatment. Round lower and upper bound of the confidence interval to 2 decimal places. Show your work.