1. What is the critical value for a 95% confidence interval based on a sample size of 20? (Population deviation is unknown)

a) 1.729133

b) 2.08596

c) 1.724718

d) 2.09302

2.A sample of 135 randomly selected students, found the proportion of students planning to travel home for Thanksgiving is 0.63.

What is the standard deviation of the sampling distribution?

3. A survey of 592 citizens found that 396 of them favor a new bill introduced by the city. We want to find a 95% confidence interval for the true proportion of the population who favor the bill.

What is the lower limit of the interval.