we have found that students who studied by giving themselves quizzes, recall a greater proportion of words than students who studied by reading. Also, we see that there is an effect but often the question of interest is not is there an effect but instead, how big is the effect to address the second question use the information given below to 99% confidence interval for the difference in proportion P1 minus P2 were P1 represents the proportion of items correctly, recalled by all students who study using a self quiz method and P2 represents the proportion of of items correctly, recalled by all students who study this study, using a reading only approach assume that the standard air for the bootstrap distribution of such difference is also about 0.0Seven The proportion of items correctly recalled was 0.15 for the reading study group and 0.42 for the self quiz group rap find the 99% confidence interval