A simple random sample of 400 households is taken in a large city, and the number of cars in each sampled household is noted. The average number of cars in the sampled households is 1.8 and the SD is 1.3. Among the sampled households, 10% had no car.

An approximate 99% confidence interval for the percent of city households that have no car goes from _____________________% to ______________________%.

Question

A simple random sample of 400 households is taken in a large city, and the number of cars in each sampled household is noted. The average number of cars in the sampled households is 1.8 and the SD is 1.3. Among the sampled households, 10% had no car.

An approximate 99% confidence interval for the percent of city households that have no car goes from _____________________% to ______________________%.