Based on a sample of 30 randomly selected years, a 90% confidence interval for the mean annual precipitation in one city is from 40.3 inches to 43.7 inches. Find the margin of error. A) 3.4 inches B) There is not enough information to find the margin of error. C) 1.7 inches D) 0.51

C) 1.7 inches

Explanation:

According to the situation, the solution of the margin of error is as follows

The Margin of error is

= 1 ÷ 2 × length of the confidence interval

where,

length of the confidence interval is from 40.3 inches to 43.7 inches

Now putting these values to the formula above

So, the margin of error is

= 1 ÷ 2 × (40.3 inches - 43.7 inches )

= 1.7 inches