The weights of running shoes are normally distributed with a population standard deviation of 3 ounces and an unknown population mean. if a random sample of 23 running shoes is taken and results in a sample mean of 18 ounces, find a 90% confidence interval for the population mean.

Step-by-step explanation:

Given : Level of significance :

Then , significance level :

Since , sample size : , which is small sample (n<30) so the test applied here is a t-test.

Sample mean :

Standard deviation:

Degree of freedom=

Using t-distribution table , Critical value :

The confidence interval for population mean is given by :-

Hence,  a 90% confidence interval for the population mean=

answer: 59

step-by-step explanation:

answer: 80,000

step-by-step explanation:

the population doubles every day.

10,000*2=20,000 day 4

20,000*2=40,000 day 5

40,000*2=80,000 day 6