Question

You measure 22 watermelons' weights, and find they have a mean weight of 36 ounces. Assume the population standard deviation is 6.9 ounces. Based on this, construct a 95% confidence interval for the true population mean watermelon weight. Give your answers as decimals, to two places

Answer 1

Explanation:

Confidence interval formula is expressed as;

CI = xbar ±(z*s/√n)

xbar is the mean = 36

z is the z score at 95% CI = 1.96

s is the standard deviation = 6.9

n is the sample size = 22

Substitute

CI = 36 ±(1.96*6.9/√22)

CI = 36 ±(1.96*6.9/4.6904)

CI = 36 ±(1.96*1.4711)

CI = 36 ± 2.8833

CI = (36 - 2.8833, 36 + 2.8833)

CI = (33.1167, 38.8833)

Hence the 95% CI for the true population mean is 33.12<x<38.88