using the z table find critical value at 95 also find confid

using the z table find critical value at 95% also find confidence interval and degree of freedom

find the mean, standard deviation, and standard error 4477+ 4980

the mean need to be caluated from the two numbers above

including assumptions and justification for the predictions.

USE JUST THE TWO NUMBERS

SHOW EVERY STEP TO RECEIVE ALL POINTS

Solution

95% CI means z = 1.96

95% CI = ( mean - z*standard error , mean + z*standard error)

Given mean + z*standard error = 4477+ 4980

So mean = 4477

z*standard error = 4980

1.96*standard error = 4980

So standard error = 4980/1.96 = 2540.82

standard error = (standard deviation)/sqrt(n)

So standard deviation = standard error*sqrt(n) = 2540.82*sqrt(n)

Put the value of n, to get standard deviation