Jill and Pete come to the bookstore and each of them can buy one English-Chinese dictionary with the probabilities of 0.7 and 0.4, respectively. Let X be the number of dictionaries bought by Jill and Pete together. Find the mean and the standard deviation of X.

Jill and Pete come to the bookstore and each of them can buy one English-Chinese dictionary with the probabilities of 0.7 and 0.4, respectively. Let X be the number of dictionaries bought by Jill and Pete together. Find the mean and the standard deviation of X.

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Related questions

Q: Alex’s times for running a mile are Normally distributed with a mean time of 5.28 minutes and a…

A: Let n1 be the sample size of alex n2 be the sample size of chris Given n1=10, n2=15 , standard…

Q: Two players, Fredo and Karl, on different teams wanted to find out who scored the higher number of…

A: Given

Q: A standardized exam's scores are normally distributed. In a recent year, the mean test score was…

A: The mean test score is 1463 and standard deviation is 315. The z-score for 1860 is,…

Q: The associate dean in the college of business at Tech is going to purchase a new copying machine for…

A: Given that mean is 125,000 copies and standard deviation of 40,000 copies. That is, μ=125000σ=40,000

Q: Wyatt earned a score of 670 on Exam A that had a mean of 750 and a standard deviation of 50. He is…

A: Here both exam A and exam B are normally distributed. We need to find the marks required in exam B…

Q: The mean and standard deviation of 200 items are found to be 60 and 20 respectively. If at the time…

Q: Two players, Fredo and Karl, on different teams wanted to find out who scored the higher number of…

A: Given the data of 2 players Fredo and Karl in the table(2.57)

Q: Q4. Suppose a poll of 15 voters is taken in a large city. The purpose is to determine x, the number…

A: As per the Bartleby guildlines we have to solve first three subparts and rest can be reposted....…

Q: Both data sets have a mean of 195. One has a standard deviation of 16, and the other has a standard…

A: Given the box plot of data sets A and B, we use the key: 15|8=158. And also given that both data…

Q: If z, and x be 2 values of a variable x and each of the remaining (n – 2) values be +), find the…

Q: Assume that adults have IQ scores that are normally distributed with a mean of μ=105 and a standard…

A: Let "X" be the IQ score of the adults.

Q: ores are normally distributed with a mean of 1518 and a standard deviation of 325. If 1 SAT score…

A: Given: μ=1518, σ=325 The corresponding z-value needed to be computed is: If 1 SAT score is randomly…

Q: Assume that adults have IQ scores that are normally distributed with a mean of u = 105 and a…

A: Normal distribution is a continuous distribution which has many real life applications. Normal curve…

Q: Write out the formula of the standard deviation of a variable called X in a population. Be sure to…

A: 1. Write out the formula of the standard deviation of a variable called X in a population. Be sure…

Q: If X N(49, 16), then the standard deviation of X equals

A: It is given that, X~N49,16. This, means that, the the random variable X follows a normal…

Q: Suppose I collect test data from two different tests, History and Calculus. Suppose the history…

A: Obtain the Z-score for the History class test.Consider the values of history test be denoted by xi,…

Q: A standardized exam's scores are normally distributed. In a recent year, the mean test score was…

A: It is given that the mean score, μ of a standardized test is equal to 1485 and the standard…

Q: a. Which player had the higher average points when compared to the other players on his team?

Q: Assume that adults have IQ scores that are normally distributed with a mean of u = 100 and a…

A: Given X is normal Distributed with mean µ = 100.0 and standard deviation σ = 15.0 now will using…

Q: The mean number of English courses taken in a two-year time period by male and female college…

A: Given data is appropriate for t-test for difference of means . because the sample size is less than…

Q: variable Y is twice th

A: It is given that mean of random variable Y is twice the mean of the random variable X. EY=2EX The…

Q: mean and the standard deviation are 10 and 2 respectively. Find the arithmetic mean and the standard…

Q: Assume you know the standard deviation of test scores is 10 and that the distribution is normal. You…

A: Given information- Population mean, μ = 20 Population standard deviation, σ = 10 Sample size, n = 16…

Q: A standardized exam's scores are normally distributed. In a recent year, the mean test score was…

A: Given data: the mean test score was 1550 and the standard deviation was 310. The test scores of four…

Q: An exam is given to all three people in an accounting department. On this exam, the mean is 102 and…

A: According to the given information, we have Mean = 102 Standard deviation = 7.5

Q: A statistics instructor gives two different tests to measure students' aptitude for statistics.…

A: We have given that, Mean1 = 22 and standard deviation1 = 5. Mean2 = 71 and standard deviation2 =…

Q: Two players, Fredo and Karl, on different teams wanted to find out who scored the higher number of…

Q: An exam has a standard deviation of σ = 5 and a mean of μ = 75.Three friends who took the exam want…

Q: Assume that adults have IQ scores that are normally distributed with a mean of u= 100 and a standard…

A: The standard normal variable Z is defined as, Z = (X – µ)/σ, where µ is the mean of the random…

Q: set of scores ranges from a low of X = 25 to a high of X = 33 and has a mean of 29. Which of the…

A: GivenRange XMin= 25Range XMax= 33

Q: A standardized exam's scores are normally distributed. In a recent year, the mean test score was…

A: Given: μ = 1537 σ = 315 n = 4 Formula Used: z-score = X-μσ The value of z-score is unusual if, it is…

Q: The monthly electric bill for a local business had a mean of 1135. The values go from 1160 to 1300…

A: Given Information: mean=1135Minimum value=1160Maximum value=1300

Q: James and Harry play baseball and each of them can score one goal with the probabilities of 0.4 and…

Q: loaded my die so that the chance of a 1 is 0.1, the chance of a 6 is 0.2, and the chances of the…

A: Use ∑P(x) =1 to find the remaining probability

Q: The arithmetic mean of runs scored by 3 batsmen Vijay, Subhash and Kumar in the series of 100…

Question

Jill and Pete come to the bookstore and each of them can buy one English-Chinese
dictionary with the probabilities of 0.7 and 0.4, respectively. Let X be the number of
dictionaries bought by Jill and Pete together. Find the mean and the standard deviation of X.

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Step by step

Solved in 2 steps with 2 images

SEE SOLUTION Check out a sample Q&A here

Similar questions

A group of 10 friends played a mini-golf competition. Eight of the friends tied for second place, each with a score of 34, and the other two friends tied for first place. Find the winning score, given that the standard deviation of the scores of all 10 friends was 1.2 and that the lowest score in golf wins.
Morgan earned a score of 275 on Exam A that had a mean of 300 and a standard deviation of 25. She is about to take Exam B that has a mean of 600 and a standard deviation of 25. How well must Morgan score on Exam B in order to do equivalently well as she did on Exam A? Assume that scores on each exam are normally distributed.
A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1537 and the standard deviation was 315. The test scores of four students selected correspond to each value. random are 1920, and 1260. Find the z-scores that The z-score for 1920 is. (Round to two decimal places as needed.) The z-score for 1260 is (Round to two decimal places as needed.)
An investor has $100 to invest, and two investments between which to divide it. If she invests the entire amount in the first investment, her return will be X, while if she invests the entire amount in the second investment, her return will be Y. Both X and Y have mean $6 and standard deviation (risk) $3. The correlation between X and Y is 0.3. a) Express the return in terms of X and Y if she invests $30 in the first investment and $70 in the second. b) Find the mean return and the risk if she invests $30 in the first investment and $70 in the second. c) Find the mean return and the risk, in terms of K, if she invests $K in the first investment and $(100 − K) in the second. d) Find the value of K that minimizes the risk in part (c). e) Prove that the value of K that minimizes the risk in part (c) is the same for any correlation ρX,Y with ρX,Y ≠ 1.
Assume that adults have IQ scores that are normally distributed with a mean of u = 105 and a standard deviation o = 15. Find the probability that a randomly selected adult has an 1Q less than 129. Click to view page 1 of the table. Click to view page 2 of the table. The probability that a randomly selected adult has an IQ less than 129 is (Type an integer or decimal rounded to four decimal places as needed.)
Suppose you wish to invest money safely and are trying to decide between stock options in two companies. The average rates of return are the same for both companies but, one company has a much larger standard deviation of its rates of return.Which company should you invest in? The company with the larger standard deviation The company with the smaller standard deviation
Solve the problem.Assume that mountain lions' weights are normally distributed with a mean of 62.6 kilograms and a standard deviation of 2.6 kilograms. If 70 mountain lions are randomly selected, find the probability that they have a mean weight between 61.9 kilograms and 62.8 pounds.
A set of sociology exam scores are reported as X values and z-scores. On this exam a score of X = 75 corresponds to a z-score of z = +2.00, and a score of X = 60 corresponds to a z-score of z = -1.00. What are the values for the mean and standard deviation
Assume that the SAT test scores are normally distributed with a mean score of 1200 and a standard deviation of 150. ACT test scores are normally distributed with a mean score of 22 and a standard deviation of 3 Mike scored 1250 on the SAT. What proportion of all test takers did Mike score higher than? If Mike scored a 1250 on the SAT and Jes scored a 26 on the ACT, then who's score is relatively better?
Test scores for a Statistics class have a mean of 81 with a standard deviation of 4. Test scores for a calculus class had a mean of 75 with a standard deviation of 3.5. Suppose a student gets an 87 on the statistics test andan 86 on the calculus test. Calculate the z-scores for each test. On which test did the student perform better relative to the other students in the class.
Q12
A professor knows that her statistics students' final exam scores have a mean of 79 and a standard deviation of 12.4. In his class, an "A" is any exam score of 90 or higher. This quarter she has 25 students in her class. What is the probability that 7 students or more will score an "A" on the final exam?