Question

The following data counts the number of letters in a person’s full name, including middle initials. For example, my full name is “Lily Y Lum”, so my name has 8 letters (length is 8). I have surveyed 11 CCSF students. Include your own name to make a dataset having 12 values.

Write your full name: __________________ Length (number of letters): ________

15, 22, 17, 9, 11, 16, 18, 13, 25, 17, 24, __length of your name__

(a). Construct the 97% confidence interval for population mean length of a student’s full name at CCSF. Show at least one decimal place.

(b). Determine the sample size needed if you want to cut the interval into a third of the length in part A.

(c). If we assume the population standard deviation, ?, for the length of a person’s full name to be 10.7. Determine the minimum sample size, ?, needed to construct a __(i)__ confidence interval for the population mean length to be have width of 4 letters. (i). Fill in the blank, choose a number between 80% to 97%. Do not choose 90% or 95%.

Answer 1