Question

A population has a mean of 200 and a standard deviation of 80. Suppose a sample of size 125 is selected and is used to estimate . Use z-table.

1. What is the probability that the sample mean will be within +/- 5 of the population mean (to 4 decimals)? (Round z value in intermediate calculations to 2 decimal places.)
   
   
2. What is the probability that the sample mean will be within +/- 14 of the population mean (to 4 decimals)? (Round z value in intermediate calculations to 2 decimal places.)

In the EAI sampling problem, the population mean is $51,500 and the population standard deviation is $5,000. When the sample size is n = 30, there is a 0.4161 probability of obtaining a sample mean within +/- $500 of the population mean. Use z-table.

1. What is the probability that the sample mean is within $500 of the population mean if a sample of size 60 is used (to 4 decimals)?
   
   
2. What is the probability that the sample mean is within $500 of the population mean if a sample of size 120 is used (to 4 decimals)?

Answer 1