What price do farmers get for their watermelon crops? In the third week of July, a random sample of41farming regions gave a sample mean ofx= $6.24per 100 pounds of watermelon. Assume thatis known to be$1.98per 100 pounds.

(a) Find a92% confidence interval for the population mean price (per 100 pounds) that farmers in this region get for their watermelon crop. What is the margin of error? (Round your answers to two decimal places.)

lower limit=$

upper limit=$

margin of error=$

(b) Find the minimal sample size necessary for a92% confidence level with maximal error of estimateE=0.35for the mean price per 100 pounds of watermelon. (Round your answer to a whole number.)

farming regions

(c) A farm brings11tons of watermelon to market. Find a92% confidence interval for the population mean cash value of this crop. What is the margin of error?Hint:1 ton is 2000 pounds. (Round your answers to the nearest dollar.)

lower limit=$

upper limit=$

margin of error=$

2.For this problem, carry at least four digits after the decimal in your calculations.

A random sample of medical files is used to estimate the proportionpof all people who have blood type B.

(a)

If you have no preliminary estimate forp, how many medical files should you include in a random sample in order to be84% sure that the point estimatepwill be within a distance of0.07fromp?

Find the critical value for84% confidence level,z_0.84,

and find the specified maximal error of estimate,E. (Round your answers to two decimal places.)

z_0.84=

E=

Compute the minimal sample sizenfor estimating the proportionpof all people who have bloodtype Bunder these restrictions. (Round your answer to a whole number.)

n=medical files

(b)

Answer part (a) only this time use the preliminary estimate that about15out of90people have blood type B. (Round your proportions to three decimal places and your minimum sample size to a whole number.)

p=

q=

n=