Question

a botanist randomly selects 40 mature lodgepole pine trees in yellowstone national park. a mean height of 68.45 feet is calculated with a margin of error of ±6.20 for a 90% confidence interval. what is the interval estimate of the population mean? a 61.61 < μ < 75.30 b 62.25 < μ < 74.65 c 62.56 < μ < 74.34 d 65.03 < μ < 71.87 e 65.35 < μ < 71.55

Explanation:

Step1: Calculate lower - bound

Subtract margin of error from sample mean.
$68.45 - 6.20=62.25$

Step2: Calculate upper - bound

Add margin of error to sample mean.
$68.45 + 6.20 = 74.65$

Answer:

B. $62.25<\mu<74.65$