SOLUTION: A random sample of 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 fol

Question 1042480: A random sample of 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:
5, 6, 7, 11, 12, 7, 5, 10, 8
Under the assumption that co-payment amounts are normally distributed, find a 90% confidence interval for the mean co-payment amount in dollars.
what is the lower limit and upper limit?

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The results are as follows:
5, 6, 7, 11, 12, 7, 5, 10, 8
Under the assumption that co-payment amounts are normally distributed, find a 90% confidence interval for the mean co-payment amount in dollars.
what is the lower limit and upper limit?
x-bar = 7.89
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ME + 1.645*2.57/sqrt(9) = 1.409
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90% CI:: 7.89-1.409 < u < 7.89+1.409
lower limit:: 6.481
upper limit:: 9.299
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Cheers,
Stan H.
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