6. A survey is taken to estimate the mean annual family income for families living in public housing in Chicago. Foi a random sample of 30 families. the annual incomes (in hundreds of dollars) are as follows 83 90 77 100 83 86 10% 64 78 92 73 122 96 60 85 70 139 56 94 84 11) 93 120 70 92 100 124 59 112 79

a) Construct a stem and lead plot of the incomes. What do you predict about the shape ol the population distribution"

b) Consuuct and interpret point estimates of and , the mean and standard deviation of the family incoines of all fanulies living in public housing in Chicago.

c) Construct and interpret a 95% confidence interval for

d) Construct a 99% confidence interval for u. Interpret the interval and compare it to the one in part (c)