4) We want to know what percent of people get their coffee from a gas station. A random sample of 50 people found that 20% had gotten their coffee from the gas station. All conditions for inference have been met.

1. What is the point estimate, the sample size and the critical z valuefor the sample?

Point estimate: ________

Sample size: __________

Critical z : ____________

1. Find a 90% confidence interval. Show your work.