
Concept explainers
Given the following
a. Compute the expected value for each distribution.
b. Compute the standard deviation for each distribution.
c. What is the probability that x will be at least 3 in Distribution A and Distribution B?
d. Compare the results of distributions A and B.
a.

Find the expected value for distribution A and distribution B.
Answer to Problem 1PS
The expected value of distribution A is 1, and distribution B is 3.
Explanation of Solution
Calculation:
The table of probability distributions for distribution A and B is given.
The formula for calculating expected value is
Here,
The expected value of distribution A is calculated by substituting the values in the above formula. It is calculated as,
The expected value of distribution B is
Thus, the expected value of distribution A and distribution B are 1 and 3, respectively.
b.

Find the standard deviation of distribution A and B.
Answer to Problem 1PS
The standard deviation for both distribution A and B is 1.22474.
Explanation of Solution
Calculation:
The standard deviation is calculated using the formula,
Here,
For distribution A,
For distribution B,
Thus, the standard deviation of distribution A and B is same, that is, 1.2247.
d.

Compare the results of the two distributions.
Answer to Problem 1PS
The mean value for distribution B is higher than distribution A but the standard deviation is same for both the distributions.
Explanation of Solution
From part a, the expected value for distribution A and B are obtained as 1 and 3, respectively. From part b, the standard deviation for both the distributions is obtained as 1.2247.
Thus, it can be said that the mean value or the expected value of distribution B is greater than that of distribution A. However, both of them have the same spread as the value of standard deviation is same.
Want to see more full solutions like this?
Chapter 5 Solutions
Basic Business Statistics, Student Value Edition
Additional Math Textbook Solutions
APPLIED STAT.IN BUS.+ECONOMICS
Introductory Statistics
Calculus for Business, Economics, Life Sciences, and Social Sciences (14th Edition)
Elementary Statistics: Picturing the World (7th Edition)
Finite Mathematics for Business, Economics, Life Sciences and Social Sciences
Intermediate Algebra (13th Edition)
- Don’t solve questionarrow_forwardDon’t solve questionsarrow_forwardFred needs to choose a password for a certain website. Assume that he will choose an 8-character password, and that the legal characters are the lowercase letters a, b, c, ..., z, the uppercase letters A, B, C, ..., Z, and the numbers 0, 1, . . ., 9. (a) How many possibilities are there if he is required to have at least one lowercase letter in his password? (b) How many possibilities are there if he is required to have at least one lowercase letter and at least one uppercase letter in his password? (c) How many possibilities are there if he is required to have at least one lowercase letter, at least one uppercase letter, and at least one number in his password?arrow_forward
- a =1500, b=1700 what is percentage of a is barrow_forwardA 12-inch bar that is clamped at both ends is to be subjected to an increasing amount of stress until it snaps. Let Y = the distance from the left end at which the break occurs. Suppose Y has the following pdf. f(y) = { (a) Compute the cdf of Y. F(y) = 0 0 y -옴) 0 ≤ y ≤ 12 1- 12 y 12 Graph the cdf of Y. F(y) 1.0 0.8 0.6 0.4 0.2 y 2 6 8 10 12 F(y) F(y) F(y) 1.01 1.0ㅏ 1.0 0.8 0.6 0.4 0.2 0.8 0.8 0.6 0.4 ཨཱུ སྦེ 0.6 0.4 0.2 2 4 6 8 10 12 (b) Compute P(Y ≤ 5), P(Y > 6), and P(5 ≤ y ≤ 6). (Round your answers to three decimal places.) P(Y ≤ 5) = P(Y > 6) = P(5 ≤ y ≤ 6) = (c) Compute E(Y), E(y²), and V(Y). E(Y) = in E(Y2) v(x) = in 2 2 2 4 6 8 10 12 y 2 4 6 8 10 12arrow_forwardA restaurant serves three fixed-price dinners costing $12, $15, and $20. For a randomly selected couple dining at this restaurant, let X = the cost of the man's dinner and Y = the cost of the woman's dinner. The joint pmf of X and Y is given in the following table. p(x, y) 15 y 12 20 12 0.05 0.10 0.35 x 15 0.00 0.20 0.10 20 0.05 0.05 0.10 (a) Compute the marginal pmf of X. x 12 Px(x) Compute the marginal pmf of Y. y Pyly) 12 15 20 15 20 (b) What is the probability that the man's and the woman's dinner cost at most $15 each? (c) Are X and Y independent? Justify your answer. X and Y are independent because P(x, y) = Px(x) · Py(y). X and Y are not independent because P(x, y) =Px(x) · Pyly). X and Y are not independent because P(x, y) * Px(x) · Py(y). X and Y are independent because P(x, y) * Px(x) · Py(y). (d) What is the expected total cost, in dollars, of the dinner for the two people? $ (e) Suppose that when a couple opens fortune cookies at the conclusion of the meal, they find the…arrow_forward
- Let X = the time between two successive arrivals at the drive-up window of a local bank. If X has an exponential distribution with λ = 1, (which is identical to a standard gamma distribution with α = 1), compute the following. (If necessary, round your answer to three decimal places.) (a) the expected time between two successive arrivals (b) the standard deviation of the time between successive arrivals (c) P(X ≤ 1) (d) P(2 ≤ X ≤ 4) You may need to use the appropriate table in the Appendix of Tablesarrow_forwardIn each case, determine the value of the constant c that makes the probability statement correct. (Round your answers to two decimal places.) USE SALT (a) (c) 0.9842 (b) P(0 ≤ Z ≤ c) = 0.3051 (c) P(CZ) = 0.1335 You may need to use the appropriate table in the Appendix of Tables to answer this question.arrow_forwardSarrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillHolt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL



