Question

To estimate the necessary sample size when no value of p is available we use p = ?

a. 1
b. 0.25
c. 0.5
d. 0.75

Answer 1

To estimate the necessary sample size without a known value of p, p = 0.5 is used because it maximizes variance, thus accounting for the largest potential sample size needed.

Step-by-step explanation:

To estimate the necessary sample size when no value of p is available, we use p = 0.5. This is because 0.5 maximizes the product of p and q = 1 - p, which in turn maximizes the variance. When calculating sample size for proportions, the formula used includes the product of p and q. Therefore, when we are unsure of the value of p, using 0.5 for both p and q ensures we are planning for the largest possible sample size that could be required.