Question: Several students are unprepared for a true/false test with 25 questions, and all of their answers are guesses. Find the mean, variance, and standard deviation

Several students are unprepared for a true/false test with 25 questions, and all of their answers are guesses. Find the mean, variance, and standard deviation for the number of correct answers that would be expected for such students. Would it be unusual for one of these students to get a good mark by guessing at least 20 correct answers? Why or why not?
Find the indicated values.

Step by Step Solution

★★★★★

3.31 Rating (160 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer

Step: 1 Unlock

Let x the number of correct answers per stud... View full answer

Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock

Step: 3 Unlock

Document Format (1 attachment)

789-S-J-P-D (1351).docx

120 KBs Word File

Students Have Also Explored These Related Statistics Questions!

You are totally unprepared for a true-false quiz, so you decide to guess randomly at the answers. There are four questions. Find the probabilities described in 10a-e. a. P(none correct) b. P(exactly...

Find the mean, variance, and standard deviation of the following data: 4, 3, 4, 6, 8, 0, 2.

There are 10 questions on a true-false test. A student feels unprepared for this test and randomly guesses the answer for each of these. (a) What is the probability that the student gets exactly 7...

Several archeology students are unprepared for a surprise true/false test with 25 questions, and all of their answers are guesses. Find the mean for the number of correct answers for such students....

Several psychology students are unprepared for a surprisetrue/false test with 9 questions, and all of their answers are guesses. a. Find the mean and standard deviation for the number of correct...

Several psychology students are unprepared for a surprisetrue/false test with 10 questions, and all of their answers are guesses . a. Find the mean and standard deviation for the number of correct...

10. Guessing Answers Several economics students are unprepared for a multiple-choice quiz with 25 questions, and all of their answers are guesses. Each question has five possible answers, and only...

Guessing Answers Several students are unprepared for a multiple-choice quiz with 10 questions, and all of their answers are guesses. Each question has five possible answers, and only one of them is...

I need help understanding these practice problems, please explain the steps. If the probability distribution for the random variable X is given in the table, what is the expected value of X? Xi - 3 1...

I JUST NEED THE ANSWER!! NO WORK NEEDED! 1.Use the given information below to find the, minimum or (min(x)) and maximum or (max(x)) usual value. (ROUND TO THE TENTHS WHEN NECESSARY!) n = 400, p = 0.2...

A market researcher for a consumer electronics company wants to study the television viewing habits of residents of a particular area. A random sample of 40 respondents is selected, and each...

A- Write a program to add the following five data bytes stored in data segment offset starting from [0800H], if the sum generates a carry , stop the adding ,and store (2B) in data segment offset...

Question: Compared with analytical duration, empirical duration is the more appropriate measure to estimate the impact of benchmark interest rate changes for a bond portfolio of: A . US agency bonds....

A study was made as to how the concentration of a certain drug in the blood, 24 hours after being injected, is influenced by age and gender. An analysis of the blood samples of 40 people given the...

Listed below are skull breadths obtained from skulls of Egyptian males from three different epochs. Use a 0.05 significance level to test the claim that the samples are from populations with the same...

Refer to the preceding exercise and use only the skull breadths from 4000 B.c. and 150 A.D. Use the Wilcoxon rank-sum test with a 0.05 significance level to test the claim that the two samples are...

The table below lists weights (lb) of plastic and food disposed in one week (from Data Set 23 in Appendix B). Use rank correlation with a 0.05 significance level to test for a correlation between...

Blake made periodic deposits into a savings account at the end of every month for 5 years. The investments were earning 7.80% compounded quarterly and grew to $12,125.00 at the end of 5 years. a....

Assume that a fair die isrolled.The sample space is{1,2,3,4,5,6,} and all the outcomes are equallylikely.Find P (l ess than 2.) Write your answer as a fraction or whole number P ( less than 2) = Let...

The common stock of Leaning Tower of Pita Inc. is selling for $80 and offers these payoffs next year: The common stock of Escapist Films sells for S25 a share and offers the following payoffs next...