Determine the sample size required to estimate a population mean to within 10 units given that the population standard deviation is 55. A confidence level of 90% is judged to be appropriate.

Question

Sample Size = 

Determine the sample size required to estimate a population mean to within 10 units given that the population standard deviation is 95. Use a confidence level of 90%.

Sample Size = 

Determine the sample size required to estimate a population mean to within 10 units given that the population standard deviation is 55. Use a confidence level of 95%.

Sample Size = 

Determine the sample size required to estimate a population mean to within 21 units given that the population standard deviation is 55. A confidence level of 90% is judged to be appropriate.

Sample Size = 

Answer 1

The formula is n= (z* sigma/ME)^2 Round up to the higher integer.

So the first is n=(1.645*95/10)^2=244.22 or 245.

Presumably you can do the rest.