Answer:
280
Step-by-step explanation:
Margin of error = critical value × standard error
Here, the margin of error is 2.
At 99% confidence, the critical value is z = 2.576.
The standard error is s / √n = 13 / √n.
2 = 2.576 (13 / √n)
2 = 33.49 / √n
√n = 16.74
n = 280.4
Rounded to the nearest person, the required sample size is 280.
