1a) Day Care Tuition A random sample of 47 four-year-olds attending daycare centers provided a yearly tuition average of $3966 and the population standard deviation of $636. Find the 99% confidence interval of the true mean. Round your answers to the nearest whole number. $ ___< μ < $ ___ b) Hospital Noise Levels Noise levels at various area urban hospitals were measured in decibels. The mean noise level in 166 ward areas was 62.9 decibels, and the population standard deviation is 4.6. Find the 90% confidence interval of the true mean. Use a graphing calculator and round the answers to one decimal place. ___ < μ < ___ c) State Gasoline Taxes A random sample of state gasoline taxes (in cents) is shown here for 8 states. 32.9 45.6 36.9 34.8 65.8 66.6 51 46.3 Use the data to estimate the true population mean gasoline tax with 98% confidence. Assume the variable is normally distributed. Round the answers to at least two decimal places. ___ < μ < ___
1a) Day Care Tuition A random sample of 47 four-year-olds attending daycare centers provided a yearly tuition average of $3966 and the population standard deviation of $636.
Find the 99% confidence interval of the true
$ ___< μ < $ ___
b) Hospital Noise Levels Noise levels at various area urban hospitals were measured in decibels. The mean noise level in 166 ward areas was 62.9 decibels, and the population standard deviation is 4.6. Find the 90% confidence interval of the true mean. Use a graphing calculator and round the answers to one decimal place.
___ < μ < ___
c) State Gasoline Taxes A random sample of state gasoline taxes (in cents) is shown here for 8 states.
|
32.9
|
45.6
|
36.9
|
34.8
|
65.8
|
|
66.6
|
51
|
46.3
|
___ < μ < ___
d) Weights of Elephants A sample of 8 adult elephants had an average weight of 12,400 pounds. The standard deviation for the sample was 20 pounds. Find the 99% confidence interval of the population mean for the weights of adult elephants. Assume the variable is normally distributed. Use a graphing calculator and round the answers to the nearest whole number.
___ < μ < ___
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