Here is a simple probability model for multiple-choice tests. Suppose that each student has probability p of correctly answering a question chosen at random from a universe of possible questions. (A strong student has a higher p than a weak student.) The correctness of answers to different questions are independent. Jodi is a good student for whom p = 0.75. (a) Use the Normal approximation to find the probability that Jodi scores 70% 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 70% or lower? (Use the normal approximation. Round your answer to four decimal places.)(c) How many questions must the test contain in order to reduce the standard deviation of Jodi's proportion of correct answers to half its value for a 100-item test? questions
Contingency Table
A contingency table can be defined as the visual representation of the relationship between two or more categorical variables that can be evaluated and registered. It is a categorical version of the scatterplot, which is used to investigate the linear relationship between two variables. A contingency table is indeed a type of frequency distribution table that displays two variables at the same time.
Binomial Distribution
Binomial is an algebraic expression of the sum or the difference of two terms. Before knowing about binomial distribution, we must know about the binomial theorem.
Here is a simple
(a) Use the Normal approximation to find the probability that Jodi scores 70% 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 70% or lower? (Use the normal approximation. Round your answer to four decimal places.)
(c) How many questions must the test contain in order to reduce the standard deviation of Jodi's proportion of correct answers to half its value for a 100-item test?
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