Posted by TIMBERLY on Thursday, April 7, 2011 at 5:35pm.
A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is 15.
a) Compute the 95 % confidence interval for the population mean.
b) Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean.
c)What is the effect of a larger sample size on the margin of error?

statistics  PsyDAG, Saturday, April 9, 2011 at 11:52am
a) 95% = mean ± 1.96 SD
b) 95% = mean ± 1.96 SEm
SEm = SD/√(n1)
c) margin of error decreases.

statistics  Anonymous, Wednesday, June 6, 2012 at 4:07pm
xz

statistics  Liyyah, Wednesday, October 28, 2015 at 6:36pm
I would really like to know this answer, i am not good at doing the calculations....can someone help please?
Answer This Question
Related Questions
 Statistics (42)  A simple random sample of 60 items resulted in a sample mean ...
 Economics (41)  A simple random sample of 60 items resulted in a sample mean of...
 Statistics  A simple random sample of 60 items resulted in a sample mean of 64...
 statistics  A simple random sample of 50 items from a population with σ ...
 Statistics  A 95% confidence interval for a population mean, ?, is given as (18...
 statistics  A simple random sample of 40 items resulted in a sample mean of 25...
 Stats  A sample of 400 items is taken from a population whose standard ...
 statistics  what are the mean and standard deviation of a sampling distribution...
 Statistics  Which of the following statements correctly interprets a 95% ...
 research statistics  Fortynine items are randomly selected from a population ...
More Related Questions