2) Here are measurements (in mm) of a critical dimension on a random sample of auto engine crankshafts:
224.120224.001224.017223.982223.989223.961
223.930224.089223.987223.976223.902223.980
224.098224.057223.913223.999
The data come from a production process that is known to had standard deviation ??= .060 mm.
a) What is the shape of the sampling distribution of ?
b) Give a 95% confidence interval for the process mean at the time these crankshafts were produced.
c) How large a sample of the crankshafts would be needed to estimate the mean ? within mm with 95% confidence?
3) A radio talk show invites listeners to enter a dispute about a proposed pay increase for city council members. “What yearly pay do you think council members should get? Call us with your number.” In all, 958 people call. The mean pay they suggest is per year. (Assume ) The station calculates the 95% confidence interval for the mean pay ? that all citizens would propose for the council members to be $8669 to $8811.
a) Is the station’s calculation correct?
b) Does their conclusion describe the population of all the city’s citizens? Explai
224.120224.001224.017223.982223.989223.961
223.930224.089223.987223.976223.902223.980
224.098224.057223.913223.999
The data come from a production process that is known to had standard deviation ??= .060 mm.
a) What is the shape of the sampling distribution of ?
b) Give a 95% confidence interval for the process mean at the time these crankshafts were produced.
c) How large a sample of the crankshafts would be needed to estimate the mean ? within mm with 95% confidence?
3) A radio talk show invites listeners to enter a dispute about a proposed pay increase for city council members. “What yearly pay do you think council members should get? Call us with your number.” In all, 958 people call. The mean pay they suggest is per year. (Assume ) The station calculates the 95% confidence interval for the mean pay ? that all citizens would propose for the council members to be $8669 to $8811.
a) Is the station’s calculation correct?
b) Does their conclusion describe the population of all the city’s citizens? Explai