Homework Help: statistics

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 ą 1.96 SD

b) 95% = mean ą 1.96 SEm

SEm = SD/√(n-1)

c) margin of error decreases.
statistics - Anonymous, Wednesday, June 6, 2012 at 4:07pm
xz

Answer this Question

Related Questions

Statistics - The null and alternate hypotheses are: H0: μ1 = μ...
statistics - A simple random sample of 25 has been collected from a normally ...
Statistics - A simple random sample of 25 has been collected from a normally ...
statistics - A simple random sample of 25 has been collected from a normally ...
statistics - A simple random sample of 50 items from a population with &#963...
statistics - 7. A sample of 40 observations is selected from one population. The...
statistics - a. A random sample of 25 was drawn from a normal distribution with ...
Statistics - 8. A sample of 65 observations is selected from one population. The...
statistics - a simple random sample will be obtained from a normally distributed...
Stats - I just need help with starting how to calculate the problem I am so lost...

For Further Reading

First Name:
School Subject:
Answer: