if Unknown confidence level of 95% is 639

as shown below

Unknown variability, confidence level of 95%

Use 50/50 for p and q.

=639.4 (639)

25

= 15,984

25

= 6.66 x 2400

5

= 2.58 (60 x 40)

e

n= z (pq)

2

2

2

2

1.What is the Unknown variability, confidence level of 90%

2.What is the Unknown variability, confidence level of 99%