Question

Suppose that a travel bureau claims that the trees in a forest are 85 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?

Answer 1

Explanation:

It is given that Suppose that a travel bureau claims that the trees in a forest are 85 feet tall on average, with a standard deviation of 0.2 feet.

Here, Mean=85, Standard deviation=0.2, Sample=64.

Now, using the confidence interval as 95%, then z=1.96.

Thus, Margin error is given as:

`ME=\frac{1.96{*}0.2}{√(64)}=(0.392)/(8)`

`ME=0.049`

Therefore, confidence interval:
`85-0.048<{\mu}<85+0.049`

that is:
`84.95<{\mu}<85.049`

Mean heights outside the confidence interval will be:

`x\leq84.95` and
`x\geq85.049`.