1. If a school district takes a random sample of 69 Math SAT scores and finds that the average is 496, and knowing that the population standard deviation of Math SAT scores is intended to be 100. Find a 99% confidence interval for the mean math SAT score for this district.

________ ____________

2. A researcher wants to know how long it takes, on average, for a certain species of bacteria to divide. She watches 20 cells through a microscope and times how long it takes them to divide. She obtains the following data, in hours: 8.1, 8.6, 8.3, 8.6, 8.7, 7.8, 8.5, 8.3, 7.8, 8.1, 8.2, 8.6, 8.3, 8.4, 8.5, 8.3, 8.9, 8.7, 7.6, 7.8 Assuming the population standard deviation is =0.3=0.3, construct a 92% confidence interval for the average time it takes this species of bacteria to divide. x=_______________ 2=_____________ z2=____________ Margin of Error: E=____________ We are 92% confident that this species of bacteria takes, on average, between_________ hours and _____________ hours to divide.