Question

1. a) Suppose average monthly sales for retail locations across the United States are approximately normally distributed with unknown mean and variance. We’ve taken n= 100 observations and found s^2= 5234.Construct a 95% confidence interval for the population variance σ^2.

b) Using the setup from part a , construct a 95% lower confidence bound for σ^2

c) You frequent a popular fast food restaurant that serves tacos...and they frequently get your order wrong. You decide to do a bit of research, so you miraculously get

a hold of n= 700 orders and realize that 242 of them were wrong. Give a 95%confidence interval for the population proportion of incorrect orders, p.

.

Answer 1