Question

A sample of 100 cans of peas shown an average weight of 14 oz with a standard deviation of 0.7 Oz. Construct a 95% confidence interval for the mean of the population.

​

Answer 1

A 95% confidence interval on the z-table is 1.96.

Now find the standard error using the formula: standard deviation / square root sample size:

0.7 / √100 = 0.07

Multiply to the confidence interval: 1.96 x 0.07 = 0.137 = 0.14

Now add and subtract tot he average weight:

14 - 0.14 = 13.86

14 + 0.14 = 14.14

The answer is 13.96 ≤ u ≤ 14.14