The level of nitrogen oxides (NOX) in the exhaust of a particular car model varies with mean 0.8 grams per mile and standard deviation 0.17 grams per mile . (a) What sample size is needed so that the standard deviation of the sampling distribution is 0.01 grams per mile

Sample size, n = 289

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 0.8 grams per mile

Standard Deviation, σ = 0.17 grams per mile

We have to find the sample size such that standard deviation of the sampling distribution is 0.01 grams per mile.

Formula:

Standard error =

Putting values, we get,

Thus, the sample size must be 289 so that the sampling distribution have a standard deviation of 0.01 grams per mile.

the answer is b.

step-by-step explanation:

by the trigonometric ratio tangent, tangent equals opposite divided by adjacent.

therefore, tan(50) equals ac/3

multiply each side by 3 to get: ac=3tan(50)

the answer is b.

$15 each

step-by-step explanation:

$45/3 children= $15 each