Question

In: Statistics and Probability

Some students have suggested that if you have to guess on a multiple-choice question, you should...

Some students have suggested that if you have to guess on a multiple-choice question, you should always choose C. Carl, the student, wants to investigate this theory. He is able to get a sample of past tests and quizzes from various teachers. In this sample there are 90 multiple-choice questions with four options (A, B, C, D). The distribution of correct answers from this sample is given in the frequency table below.

Correct Answer Frequency:

A 19

B 23

C 27

D 21

(a) If the correct answers for all multiple-choice problems are uniformly distributed across the four options (A, B, C, D), what is the theoretical proportion of those which should have the answer C? Express your answer as an exact decimal, not a percentage.

(b) Based on the sample that Carl collected, what is the point estimate for the proportion of all multiple-choice questions with a correct answer of C? Round your answer to 3 decimal places.

(c) Construct the 95% confidence interval for the proportion of all multiple-choice questions with a correct answer of C? Round your answers to 3 decimal places.

(d) Can Carl be 95% confident that the correct answer of C shows up more frequently than the theoretical value found in part (a) would suggest?

a. No, because 0.25 is within the confidence interval limits.

b. Yes, because 0.25 is below the lower limit of the confidence interval.

c. No, because 0.25 is below the lower limit of the confidence interval.

d. Yes, because 0.25 is within the confidence interval limits.

Solutions

Expert Solution

(a) If the correct answers for all multiple-choice problems are uniformly distributed across the four options (A, B, C, D), what is the theoretical proportion of those which should have the answer C? Express your answer as an exact decimal, not a percentage.

1/4 = 0.25

(b) Based on the sample that Carl collected, what is the point estimate for the proportion of all multiple-choice questions with a correct answer of C? Round your answer to 3 decimal places.

27/90 = 0.3

(c) Construct the 95% confidence interval for the proportion of all multiple-choice questions with a correct answer of C? Round your answers to 3 decimal places.

Observed
0.3 p (as decimal)
27/90 p (as fraction)
27. X
90 n
0.0527 std. error
0.205 confidence interval 95.% lower
0.395 confidence interval 95.% upper
0.0947 margin of error

(0.205, 0.395)

(d) Can Carl be 95% confident that the correct answer of C shows up more frequently than the theoretical value found in part (a) would suggest?

d. Yes, because 0.25 is within the confidence interval limits.


Related Solutions

Multiple Choice Strategy: Some students have suggested that if you have to guess on a multiple-choice...
Multiple Choice Strategy: Some students have suggested that if you have to guess on a multiple-choice question, you should always choose C. Carl, the student, wants to investigate this theory. He is able to get a sample of past tests and quizzes from various teachers. In this sample there are 80 multiple-choice questions with four options (A, B, C, D). The distribution of correct answers from this sample is given in the frequency table below. Correct Answer Frequency A 15...
Multiple Choice Strategy: Some students have suggested that if you have to guess on a multiple-choice...
Multiple Choice Strategy: Some students have suggested that if you have to guess on a multiple-choice question, you should always choose C. Carl, the student, wants to investigate this theory. He is able to get a sample of past tests and quizzes from various teachers. In this sample there are 90 multiple-choice questions with four options (A, B, C, D). The distribution of correct answers from this sample is given in the frequency table below. Correct Answer Frequency A 16...
some have suggested that Medicare should be referred to as _____ rather than an entitlement.
some have suggested that Medicare should be referred to as _____ rather than an entitlement.
Does a student just guess on a multiple-choice test or do they actually understand the material?...
Does a student just guess on a multiple-choice test or do they actually understand the material? An instructor gives an exam that consists of 100 multiple-choice questions. Each question has four possible answers. The student in question completes all 100 questions. The result is that the student has 31 of the answers correct. Does this provide sufficient evidence to rule out random guessing by the other student? Conduct an appropriate test of hypothesis, providing assumptions, hypothesis, test statistic, p-value, and...
Some have suggested that the Sherman Act should be amended to exempt the NCAA, colleges, and...
Some have suggested that the Sherman Act should be amended to exempt the NCAA, colleges, and universities. Should Congress enact such an exemption? Why or why not?
There is a multiple choice question with 4 choices. Many students got the problem wrong. Out...
There is a multiple choice question with 4 choices. Many students got the problem wrong. Out of a class of n=60 only 20 got the problem right (1/3 or p=.3333). Prof. K wants to determine if the students answered the question correctly more frequently than chance, i.e., the null hypothesis is 1/4 or p=.25). Does the success/failure criterion hold? What conditions might invalidate the independence requirement? i) students copying each other's answers ii) different sections taking the test on different...
Multiple Choice question on Auditor's Report
The section of the annual report that is the report of the independent registered public accounting firm is often referred to as the  A. Auditor's Report B. Management's discussion and Analysis of Financial condition and results           of operations Report C.Business Overview Report D.Notes to Financial statements Report
A student is given 20 multiple choice questions. Each multiple choice question has 4 options &...
A student is given 20 multiple choice questions. Each multiple choice question has 4 options & only one correct answer. The student answers all the questions in a random manner. a) What is the probability the student scores 80% or above? b) What is the probability the student scores 50% or above?
Multiple Choice Identify the choice that best completes the statement or answers the question. ____     6.  ...
Multiple Choice Identify the choice that best completes the statement or answers the question. ____     6.   Which of the following observations is true? a. State governments are the shareholders of the Fed. b. The Fed chairman is appointed for a ten year term. c. FOMC decisions largely determine short-term interest rates. d. Member banks proportionately share all of Federal Reserve's profits. ____     7.   In making policies about the nation's money supply, the Federal Reserve Board a. operates as an independent...
Suppose you take a 30 question test, multiple choice, with each question having 4 choices. A,...
Suppose you take a 30 question test, multiple choice, with each question having 4 choices. A, B, C, D. If you randomly guess on all 30 questions, what is the probability you pass the exam (correctly guess on 60% or more of the questions)? Assume none of the questions have more than one correct answer. b) what the expected number of correct guesses? what is the standard deviation? c) what would be considered an unusual number of correct guesses on...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT