Answer:
a)
And rounded up we have that n=4161
b)
And rounded up we have that n=640
Step-by-step explanation:
Part a
The confidence level is 99% , our significance level would be given by and . And the critical value would be given by:
The margin of error for the proportion interval is given by this formula:
(a)
And on this case we have that and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
Since we don't have prior info for the true proportion we can use . And replacing into equation (b) the values from part a we got:
And rounded up we have that n=4161
Part b
For this case we have a prior estimation ofr the proportion:
And replacing we got:
And rounded up we have that n=640