Answer:
This will decrease the margin of error associated with your 90% confidence interval.
Step-by-step explanation:
Margin of error:
The margin of error of a confidence interval is given by a formula that follows the following format:
In which z is related to the confidence level, s is related to the standard deviation and n is related to the size of sample.
From the formula:
M and n are inversely proportional, which means that if the sample size is increased, the margin of error decreases.
In this question:
Sample size increases from 5 to 10, so the margin of error decreases.