3.
1000 miles per month.
12 months in a year.
1000 × 12 = 12000 miles per year
Oil change every 4000 miles.
12000 ÷ 4000 = 3
Therefore 3 oil changes per year.
24/4: 24-12: 12+0: 12/1: 48/4: 72/6:
Answer:

Step-by-step explanation:
The missing parameters are:
--- population
--- population mean
-- population standard deviation
Required

First, calculate the sample standard deviation




Next, calculate the sample mean 

So:

So, we have:



Calculate the z score




So, we have:

From the z table

So:
