A random sample of 13 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:
11 5 7 8 10 5 12 11 12 12 10 8 5
Under the assumption that co-payment amounts are normally distributed, find a 95% confidence interval for the mean co-payment amount in dollars.
Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.
Upper and lower limit confidence interval please.
11 5 7 8 10 5 12 11 12 12 10 8 5
Under the assumption that co-payment amounts are normally distributed, find a 95% confidence interval for the mean co-payment amount in dollars.
Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.
Upper and lower limit confidence interval please.
-
2.6446328365648 is the standard deviation.
A 95 confidence interval means that the prediction is within two standard deviations of the mean. so the mean of your population is 8.92, and the standard deviation is 2.64. thus your 95% confidence interval is:
8.92+(2.64*2) 14.2
8.92-(2.64*2) -> 3.64
Calculations were done in Microsoft Math, see ref 2.
mean({11,5,7,8,10,5,12,11,12,12,10,8,5…
8.9230769230769
stdDev({11,5,7,8,10,5,12,11,12,12,10,8…
sqrt(1182)/13 or 2.6446328365648
A 95 confidence interval means that the prediction is within two standard deviations of the mean. so the mean of your population is 8.92, and the standard deviation is 2.64. thus your 95% confidence interval is:
8.92+(2.64*2) 14.2
8.92-(2.64*2) -> 3.64
Calculations were done in Microsoft Math, see ref 2.
mean({11,5,7,8,10,5,12,11,12,12,10,8,5…
8.9230769230769
stdDev({11,5,7,8,10,5,12,11,12,12,10,8…
sqrt(1182)/13 or 2.6446328365648