Q1. Show that for a sample of n = 39, the smallest and largest Z values are - 1.96 and + 1.96, and the middle (i.e., 20th) Z value is 0.00.
Q2. The data in the file spending represent the per-capita spending, in thousands of dollars, for each state in 2004. Decide whether the data appear to be approximately normally distributed by:
A. Comparing data characteristics to theoretical properties.
B. Constructing a normal probability plot.
Q3. For a population containing N=902 individuals what code number would you assign for
(a)The first person on the list?
(b) The fortieth person on the list?
(c)The last person on the list?
Q4. Prenumbered sales invoices are kept in a sales journal.The invoices are numbered from 0001 to 5000.
(a) beginning in row 16,column 1,and proceeding horizontally in Table E.1,select a sample of 50 invoice numbers.
(b) select a systematic sample of 50 invoice numbers. Use the random numbers in row 20,columns 5-7 ,as the starting point for your selection.
(c) Are the invoices selected in (a) the same as those selected in(b)?why or why not?
Q5. The diameter of a brand of ping-pong ball is approximately normally distributed, with a mean of 1.30 inches and a standard deviation of 0.04 inch. If you select a random sample of 16 ping-pong balls,
(a) What is the sampling distribution of the mean?
(b) What is the probability that the sample mean is less than 1.28 inches?
(c)what is the probability that the sample mean is between 1.31 and1.33 inches?
(d) The probability is 60% that the sample mean is between will be between what two values, symmetrically distributed around the population mean?