A random sample of 14 health maintenance organizations (HMOs) was selected. For each HMO, the co-payment (in dollars) for a doctor's office visit was recorded. The results are as follows.

9, 6, 6, 11, 7, 7, 7, 6, 5, 9, 8, 11, 5, 12

Under the assumption that co-payment amounts are normally distributed, find a 90% confidence interval for the mean co-payment amount in dollars. Then find the lower limit and upper limit of the 90% confidence interval.

Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. (If necessary, consult a list of formulas.)

Lower limit: $_____

Upper limit: $_____