In a random sample of 25 laptop computers the mean repair cost was $150 with a standard deviation of $35. Compute the 99% confidence interval for u

Step-by-step explanation:

Information given

represent the sample mean for the sample  

population mean

s=35 represent the sample standard deviation

n=25 represent the sample size  

Confidence interval

The confidence interval for the mean is given by the following formula:

  (1)

In order to calculate the critical value we need to find first the degrees of freedom, given by:

Since the Confidence is 0.99 or 99%, the value of and and the critical value for this case

Now we have everything in order to replace into formula (1):

y > 1/3x

y < = -x + 4

hope this : )