What is the value of the test statistic, z? Show work and final answer as 2 decimal places.

Answer 1

Hi Lovely,

In order to calculate the test statistic z, you will need to know the x value, the population mean µ and the standard deviation σ. If the sample size n>30, you can use the sample standard deviation s as an estimate for σ) .

The equation for z is:

z = (x-µ)/σ

OR

z =(x-µ)/s

Or, for a sampling distribution, you will also need to know n, and then calculate:

z = (x-µ)/(σ/√n).

For example, let's say you're told a population has µ = 100 and σ = 2. You want to find the z-statistic for an x-value of 105. You would calculate:

z = (105-100)/2 = 2.5

Hope that helps!

Steph