A simple random sample of 50 items from a population with standard dev=7 resulted in a sample mean of 36.
If required, round your answers to two decimal places.
a. Provide a 90% confidence interval for the
population mean.
to
b. Provide a 95% confidence interval for the
population mean.
to
c. Provide a 99% confidence interval for the population mean.
Solution :
Given that,
= 36
= 7
n = 50
a ) At 90% confidence level the z is ,
= 1 - 90% = 1 - 0.90 = 0.10
/ 2 = 0.10 / 2 = 0.05
Z/2 = Z0.05 = 1.645
Margin of error = E = Z/2* (/n)
= 1.645 * (7 / 50 )
= 1.63
At 90% confidence interval estimate of the population mean is,
- E < < + E
36 - 1.63< < 36 + 1.63
34.37< < 37.63
(34.37, 37.63 )
b ) At 95% confidence level the z is ,
= 1 - 95% = 1 - 0.95 = 0.05
/ 2 = 0.05 / 2 = 0.025
Z/2 = Z0.025 = 1.960
Margin of error = E = Z/2* (/n)
= 1.960 * (7 / 50 )
= 1.94
At 95% confidence interval estimate of the population mean is,
- E < < + E
36 - 1.94< < 36 + 1.94
34.06< < 37.94
(34.06, 37.94 )
c ) At 99% confidence level the z is ,
= 1 - 99% = 1 - 0.99 = 0.01
/ 2 = 0.01 / 2 = 0.005
Z/2 = Z0.005 = 2.576
Margin of error = E = Z/2* (/n)
= 2.576 * (7 / 50 )
= 2.55
At 90% confidence interval estimate of the population mean is,
- E < < + E
36 - 2.55< < 36 + 2.55
33.46< < 38.55
(33.45, 38.55 )
A simple random sample of 50 items from a population with standard dev=7 resulted in a sample...
A simple random sample of 60 items from a population with = 7 resulted in a sample mean of 35. If required, round your answers to two decimal places. a. Provide a 90% confidence interval for the population mean. to b. Provide a 95% confidence interval for the population mean. to c. Provide a 99% confidence interval for the population mean.
A simple random sample of 80 items from a population with o = 7 resulted in a sample mean of 37. If required, round your answers to two decimal places. a. Provide a 90% confidence interval for the population mean. to b. Provide a 95% confidence interval for the population mean. to c. Provide a 99% confidence interval for the population mean. to
A simple random sample of 70 items from a population with o 9 resulted in a sample mean of 39 If required, round your answers to two decimal places. a. Provide a 90% confidence interval for the population mean. to b. Provide a 95% confidence interval for the population mean. to c. Provide a 99% confidence interval for the population mean. to
A simple random sample of 90 items from a population with = 9 resulted in a sample mean of 38. If required, round your answers to two decimal places. a. Provide a 90% confidence interval for the population mean. to b. Provide a 95% confidence interval for the population mean. to c. Provide a 99% confidence interval for the population mean. to Sales personnel for Skillings Distributors submit weekly reports listing the customer contacts made during the week. A sample...
A simple random sample of 40 items resulted in a sample mean of 30. The population standard deviation is o = 15. a. Compute the 95% confidence interval for the population mean. Round your answers to one decimal place. b. Assume that the same sample mean was obtained from a sample of 90 items. Provide a 95% confidence interval for the population mean. Round your answers to two decimal places.
A simple random sample of 30 items resulted in a sample mean of 50. The population standard deviation is σ = 10. a. Compute the 95% confidence interval for the population mean. Round your answers to one decimal place. Enter your answer using parentheses and a comma, in the form (n1,n2). Do not use commas in your numerical answer (i.e. use 1200 instead of 1,200, etc.) b. Assume that the same sample mean was obtained from a sample of 90...
A simple random sample of 80 items from a population with σ =7 resulted in a sample mean of 35. If required, round your answers to two decimal places. a. Provide a confidence interval for the population mean. b. Provide a confidence interval for the population mean. c. Provide a confidence interval for the population mean.
A simple random sample of 50 items resulted in a sample mean of 30. The population standard deviation is σ = 10. a. Compute the 95% confidence interval for the population mean. Round your answers to one decimal place. Enter your answer using parentheses and a comma, in the form (n1,n2). Do not use commas in your numerical answer (i.e. use 1200 instead of 1,200, etc.) b. Assume that the same sample mean was obtained from a sample of 100...
A simple random sample of 40 items resulted in a sample mean of 60. The population standard deviation is σ =20 . a. Compute the 95% confidence interval for the population mean. Round your answers to one decimal place. ( , ) b. Assume that the same sample mean was obtained from a sample of 130 items. Provide a 95% confidence interval for the population mean. Round your answers to two decimal places. ( , )
A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is σ =15 . a. Compute the 95% confidence interval for the population mean. Round your answers to one decimal place. ( , ) b. Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean. Round your answers to two decimal places. ( , )