Question

Two competing toothpaste brands both claim to produce the best toothpaste for whitening. A dentist randomly samples 48 patients that use Brand A (Group 1) and finds 30 of them are satisfied with the whitening results of the toothpaste. She then randomly samples 45 patients that use Brand B (Group 2) and finds 33 of them are satisfied with the whitening results of the toothpaste. Construct a 99% confidence interval for the difference in proportions and use it to decide if there is a significant difference in the satisfaction level of patients Enter the confidence interval - round to 3 decimal places. <P1-P2 Can it be concluded that there is a difference in the proportions?

Answer 1

DATE Ans Brand B Brand A na-45 48 interval for difterenie becho can fas, 9 tuo on fidenie Means- 30 O.625 48 33 R2 0.733 11 45 2 2- vitical Valu fors 99 /. T 2.576 in temval is 99 con fiden ce n2 o.625(1-0.625 0.733((-0.733 t 2.576 6.625-0.733 248 45 + 0.108 0.24750984 (-o.356 0.139 P-P2 0. 139 0.356 ince the con fiden ce in temval tontains 2e Hence auept Ho Thus in the pruportians There is no diftersence