Answer: 2.845
Explanation:
The formula to find the standard deviation is given by :-
, where p is the probability of getting success in each trial and n is the sample size.
Given : Sample size : n=110
The proportion of employees older than 55 and considering retirement : p=0.08
Then, the standard deviation is given by :-

Hence, the standard deviation for the sampling distribution of the sample proportions is 2.845.