Question

A 90% confidence interval for the average weight (in pounds) of Americans was found to be (185, 210). The point estimate for this confidence interval is:_______

a. 25
b. 12.5
c. 197.5
d. 1.645

Answer 1

B. 12.5

Explanation:

We have the lowe confidence interval = 185

The upper confidence interval = 210

Mean of X = (lower confidence + upper confidence interval)/2

Mean of X = 185 + 210/2

= 197.5

The margin of error = the upper confidence interval - mean of X

= 210-197.5

= 12.5