Answer: 13
Step-by-step explanation:
If the prior population proportion is unavailable then the formula to find the sample size is given by :-
, where z* = Critical z-value
E = margin of error
Let p be the proportion of Americans who support the gun control in 2018.
As per given , we have
Confidence level = 99%
The critical z-value for 99% confidence interval is 2.576 ( BY z-table)
Margin of error : E= 0.36
Since there no prior information about the proportion of Americans who support the gun control in 2018.
So , the required sample size to estimate 99% confidence interval would be:
Hence, 13 Americans should be surveyed.