Question

You measure 28 backpacks' weights, and find they have a mean weight of 43 ounces. Assume the population standard deviation is 6.7 ounces. Based on this, construct a 95% confidence interval for the true population mean backpack weight.

Give your answers as decimals, to two places

±±  ounces

Answer 1

Solution :

Given that,

Sample size = n = 28

Z_/2 = 1.96

Margin of error = E = Z_/2* ( /n)

= 1.96 * (6.7 / 28)

= 2.48

At 95% confidence interval estimate of the population mean is,

- E < < + E

43 - 2.48 < < 43 + 2.48

40.52 < < 45.48

(40.5 ounces , 45.48 ounces)