Answer:
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
[tex]H_0: p_1-p_2 =0\\\\H_a: p_1-p_2 \neq 0[/tex]
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.