A survey of 100 businesses revealed that the mean after-tax ...

[stevenposner]

A survey of 100 businesses revealed that the mean after-tax profit was 80,000 . Assume the population standard deviation is 15,000:
 a. Determine the 95 confidence interval estimate of the mean after-tax profit for all businesses.
  b. Explain why you can use the confidence interval formula here, even though the population is not necessarily normal.

Question 2

The total variation in y is equal to SSR + ___________________ _.
 Fill in the blank(s) with correct word

[asdfasdf]

Answer to Question 1

a. LCL = 77,060 and UCL = 82,940.
b. By the Central Limit Theorem, as long as n is large (and 100 is considered large), the sample means have an approximate normal distribution.

Answer to Question 2

SSE
sum of squares for error

[stevenposner]

Great answer, keep it coming

[nyrave]

Thanks for the timely response, appreciate it