Answer:
972 junior executives should be surveyed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
The margin of error is of:
35% of junior executives left their company within three years.
This means that
0.95 = 95% confidence level
So , z is the value of Z that has a pvalue of
, so
.
To update this study, how many junior executives should be surveyed?
Within 3% of the proportion, which means that this is n for which M = 0.03. So
Rounding up:
972 junior executives should be surveyed.