Question

a question chosen at random from a universe strong student has a higher p than a possible questions Herd d T upPose that s probabilityP 64 (a) Use the Normal approximation to find the probability that e . cores 79% or lower on a 100-question test. (Round your answer to four decimal places.) (b) If the test contains 250 questions, what is the probability that Jodi will score 79 % or lower? (Use the normal approximation. Round your answer to four decimal places.) (c) How many questions must the test contain questions order to reduce the standard deviation of Jodi's proportion of correct answers to half its value for 100-item test? eaker student for whom p- 0.79. Does the answer you gave in (c) for standard deviation of Jodi's score apply to Laura's standard deviation also? (d) Laura Yes, the smallier o for Laura has no effect on the relationsship between the number of questions and the standard deviation. No, the smaller p for Laura alters the relationship between the number of questions and the standard deviation.

Answer 1

Solutior that Jodi ScoreS O locoor prokability on a a) The TOSt Giver P 0.84 09 r 100 By approxi maton nomal PCI-P) 0 9 0.84 0-84 C1-084) 00 -0 05 0 1344 - 0 05 J 0.00134 0.05 0 036660605 - 3638 61814 - 37 P( 3) 0 0853

he pro bability wi Scove at Jodi Here 0 50 P 0.84 p 0. 19 approxiration rosal J PC P) 0 19 0.84 0.84 C1-0.84) 950 -0 05 0.1344 950 -0.05 0. 0005316 - 0 O5 0.08318620 Q- 156 45483 2 2.1G

c TO veduce to half tbe Value tte Stondod devation Cwould inceoge its Value eg x 100 f P 9 Smale p for kaura no effect on e relatonSkip yes, he no of Quesio & Standard denation buo be