If a 90% confidence interval for the difference of proportions contains some positive and some negative values, what can we conclude about the relationship between p1 and p2 at the 90% confidence level?
a. there is a negative difference between p1 and p2.
b. there is no difference between p1 and p2.
c. there is a positive difference between p1 and p2.
d. we cannot make a conclusion about the relationship between p1 and p2.

b. There is no difference between p1 and p2.

Step-by-step explanation:

Given that a 90% confidence interval for the difference of proportions contains some positive and some negative values

i.e. confidence interval lower bound is negative and upper bound is positive

This confirms that 0 is contained in the confidence interval for difference of proporitons at 90%

Hence for the hypotheses

we find that 0 is inside the confidence interval

This implies null hypothesis is accepted

Hence we conclude that there is no difference

b. There is no difference between p1 and p2.

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