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In Problems 1–6, find the mean, variance, and standard deviation.
3.
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Chapter 11 Solutions
EP CALCULUS F/BUS.,ECON.-BRIEF-ACCESS
- 1. In an epidemic, the probability of having S|D is 0.2 and P(D) = 0.1. P(S|D') = 0.04 and P (D') = 0.01. What is the P(D|S)? 2. The relationship between weight and age was found to have a linear relationship, with expression weight= 3.0 (age) +10. Predict the weight of a girl whose age is 20 years? 3. A. If a z score of 1.95 is equal to a p of 0.9744, what proportion is greater than1.95 B. From question A, what proportion is between the mean and 1.95? 4. If a the constant for a regression is 0.8 and the standard deviation for the x variables is 4 while the standard deviation for the y variables is 6. What is the correlation coefficient r? 5. In a class of 20 students, twelve take mathematics and genetics, while eight take genetics only. What is the probability of selecting a student who takes only mathematics?arrow_forward1 b) For any data set, approximately 95% of the observations fall in the interval (T − 2s, T+2s). True Falsearrow_forwardSuppose that approximately 40% of the population has Type O+ blood. You take a sample of 5 persons. Let Y denote the number of persons in the sample with Type O+ blood. Find each of the following. (a) Pr{Y = 2} = (b) Pr{Y < 2} = (c) Pr{Y ≥ 2} =arrow_forward
- Suppose X and Y are two independent variables with variance 1. Let Z = X+bY where b > 0. If Cor(Z, Y ) = 1/2, what is the value of b?arrow_forwardProblem 1. A civil engineer is studying a left-turn lane that is long enough to hold seven cars. Let X be the number of cars in the lane at the end of a randomly chosen red light. The engineer believes that the probability that X = x is proportional to (x+1)(8 - x) for x = 0, 1, - --, 7. (A) Find the PMF of X. (B) Find the probability that X is at least five.arrow_forwardSituation 9. Suppose that X has a lognormal distribution with parameters 0 = -2 and ² = 9. Determine the following: 18. P(500 x) = 0.1 20. The variance of X.arrow_forward
- E and F are independent variables with variances of 7 and 9, respectively. Given this, Var(2E - F + 2) = ? Show complete solution.arrow_forwardSuppose X and Y are independent, X has mean 5 and variance 9, Y has mean -3 and variance 6. Compute a. E[(3X + 2Y)(X + 4Y + 7)]. b. Var [6XY]arrow_forwardSuppose f(x) = 0.125x for 0 < x < 4. determine the mean and variance of X. Round your answers to 3 decimal places. Part 1 E(X)arrow_forward
- 7. Suppose the distribution of waiting times (in hours) for residents of a particular province trying to book a vaccination appointment is determined by the function 5 5t f (t) ==e¯6, t >0 Find the percentage of residents who wait longer than the mean waiting time. In a sample of 1250 residents, we expect that the number of residents who wait longer than the median waiting time will bearrow_forwardIf E(x; – X)² fi = 600 and E fi = 30 , The variance value is equal toarrow_forward10 – 11. Margaret, an archeologist, is conducting a test to determine if there is a positive linear relationship between the total height of a dinosaur and its leg length. Her random sample of 15 dinosaur total heights (in feet) and leg lengths (in feet) produced the results shown in the following TI calculator screen. Use the TI calculations in the screen shot to help you answer questions: 10 & 11. LinReg y=a+bx a=28.67845743 b=5.639892354 r=559696513 r=.7481286741 10. What would you predict for a dinosaur's total height (to 2 decimal places) in feet, if the leg length is 5.8 feet? a) 61.39 feet b) 28.68 feet c) 114.99 feet d) 61.33 feet e) 74.81 feet 11. What percent of variation in the dinosaur's total height can be accounted for by the variation in the dinosaur's leg length? a) 28.68% b) 5.64%% c) 55.97% d) 74.81% e) none of thesearrow_forward
- Discrete Mathematics and Its Applications ( 8th I...MathISBN:9781259676512Author:Kenneth H RosenPublisher:McGraw-Hill EducationMathematics for Elementary Teachers with Activiti...MathISBN:9780134392790Author:Beckmann, SybillaPublisher:PEARSON
- Thinking Mathematically (7th Edition)MathISBN:9780134683713Author:Robert F. BlitzerPublisher:PEARSONDiscrete Mathematics With ApplicationsMathISBN:9781337694193Author:EPP, Susanna S.Publisher:Cengage Learning,Pathways To Math Literacy (looseleaf)MathISBN:9781259985607Author:David Sobecki Professor, Brian A. MercerPublisher:McGraw-Hill Education
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