7. A random sample of 13 parking meters (out of 150 parking meters total) in a beach community showed the following incomes for a day. Assume the incomes are normally distributed.

$3.60 $4.50 $2.80 $6.30 $2.60 $5.20 $6.75 $4.25 $8.00 $3.00 $9.25 $4.25 $7.50

a) Find a 90% confidence interval for the MEAN income of all parking meters in the beach community. b) Notice that most of the incomes above are NOT in the confidence interval. Explain why we don't expect them to be in the interval by explaining what the confidence interval is estimat