Question

The coffee and soup machine at the local subway station is supposed to fill cups with 6 ounces of soup. Ten cups of soup are bought with results of a mean of 5.93 ounces and a standard deviation of 0.13 ounces. How large a sample of soups would we need to be 95 percent confident that the sample mean is within 0.03 ounces of the population mean?

97

96

73

62

10

Answer 1

We have given here,              
              
standard deviation =0.13
Margin of error =E=0.03
Level of significance =   0.05
Z critical value is (by using Z table)=   1.96
Sample size formula is               


=72.13
Therefore, sample size approximately will be 73