Homework SourseSuppose the population standard deviation is 5 an SRS of n
Suppose the population standard deviation is = 5, an SRS of n = 100 is obtained, and the confidence level is chosen to be 98%. The margin of error for estimating a mean is given by 1.1650. To reduce the margin of error to 0.3883 you should:
| a) | reduce the sample to one third of its current size. |
| b) triple the sample size. | |
| c) quadruple the sample size. | |
| d) increase the sample size nine fold |
Solution
d.) Increase the sample size nine folds
1.165 = Z × 5/100
Z = 2.33
0.3883 = 2.33 × 5/n
n = 2.33 × 5/0.3883 =30
Therefore n = 900
