Hello Sir/Mam I am am new to statistics and probability. please help me figure out if I even understand this question I am very losttt...

Pleaseeee and thank youuu

1

A student who is studying journalism has been curious about the average rates paid to a person who is working as a freelancers by online magazines. She goes ahead to learn more when takes a random sample of 71 online web publications and computes together a mean rate per word of 9 cents, with a sample standard deviation of 3 cents. The student now wants to use this sample information to now find a 90% confidence interval for the average pay rate per word.

Round all final answers to 3 decimal places.

a. What is the critical t-value that will need to be used to calculate the confidence interval? ___________

b. What is the 90% confidence interval? ______

2.

A butcher shop manager has been wanting to know about how much on an average customers spend per visit that they make. From previous researchs done it suggests that the population standard deviation is $10.48. And the manager has found a mean value of the amount $71.00 for a random sample of the 40 customers, So now wants to construct a 95% confidence interval for the mean value.

Round your answers to 3 decimal places where appropriate.

(a) What is the critical z-value that will need to be used to calculate the confidence interval?

___________________

(b) What is the 95% confidence interval?

___________________

(c) If the manager wants a margin of error within $1, how large of a sample size will they need?

________________________