Answer:
The margin of error is multiplied by 1.41, which is 1 divided by the square root of 5.
Explanation:
The margin of error is:

In which z is related to the confidence level,
is the standard deviation of the population and n is the size of the sample.
The margin of error is inverse proportional to the square root of the sample size.
Then
Sample size n:

Modified(half the sample size):

Ratio

The margin of error is multiplied by 1.41, which is 1 divided by the square root of 5.