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.

3/4 ÷ 3/4

step-by-step explanation:

basically divide any proper fraction with itself to fit the criteria.

so if we are using 3/4, then:

3/4 ÷ 3/4 = 1

so 1 is the quotient.

and the numerators for both these fractions is 3.   and if we divide the numerators:

3 ÷ 3 = 1

we see that quotient is equal to our original quotient as well.