Question

Suppose that a travel bureau claims that the trees in a forest are 83 feet tall on average, with a standard deviation of 0.2 feet. If you took a sample of 64 trees, which of the following mean heights would be outside the 95% confidence interval?

A. 83.2 Feet
B. 83.4 Feet
C. 83.6 Feet
D. 82.8 Feet

Answer 1

Answer: 83.6

Explanation:

Answer 2

Explanation:

Given mean = 84,

Standard deviation = 2,

Sample 64,

95% confidence interval: z = 1.96

Applying empirical rule , means that 95% of data fall within two standard deviations.

ME =
`1.96*(2)/(√(8))` = 0.49

Rounding this to 0.5

CI = 83.5< mean < 84.5

Outside of this range= x ≤ 83.5 and ≥ 84.5