Which of the following is not a condition for constructing a confidence interval to estimate the difference between two population proportions? The samples must be selected randomly.

The samples must be selected randomly.
A

The data must come from populations with approximately normal distributions.

The data must come from populations with approximately normal distributions.
B

When samples are taken without replacement, each population must be at least 10 times as large as its corresponding sample.

When samples are taken without replacement, each population must be at least 10 times as large as its corresponding sample.
C

The samples must be independent of each other.

The samples must be independent of each other.
D

The observed number of successes and failures for both samples must be at least 10.