Using the telephone numbers listed in your local directory as your population, randomly obtain 20 samples of size. I have attached these numbers in an excel sheet. From each telephone number identified as a source, take the fourth, fifth, and sixth digits.
a. Calculate the mean of the 20 samples
b. Draw a histogram showing the 20 sample means. (Use classes -0.5 to 0.5, 0.5 to 1.5, 1.5 to 2.5 and so on).
c. Describe the distribution of the x-bars that you see in part b (shape of distribution, center, and the amount of dispersion).
d. Draw 20 more samples and add the 20 new x-bars to the histogram in part b. Describe the distribution that seems to be developing.
I need to expand sample size by another 20 phone numbers and then chart the means for all 40 phone numbers. I have added 20 additional phone numbers.
From a local telephone directory, on a sample of few randomly selected numbers some statistical analysis is carried out.