MATHS EXAM TESTED QUESTIONS AND SOLVED ANSWERS

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MATHS EXAM TESTED QUESTIONS AND SOLVED ANSWERS If random variable X has a binomial distribution with n =8 and P(success) = p =0.5, find the probability that X is at most 3. (That is, find P(X ≤ 3... )) (round to 4 decimal places) Question 2 of 20 0.0/ 1.0 Points Approximately 10% of all people are left-handed. Out of a random sample of 15 people, what is the probability that 4 of them are left-handed? Round answer to 4 decimal places. Question 3 of 20 0.0/ 1.0 Points If random variable X has a binomial distribution with n=9 and P(success) =p= 0.4, find the standard deviation of X. (round to 4 decimal places) Question 4 of 20 0.0/ 1.0 Points It is known that 20% of adult workers have a high school diploma. If a random sample of 10 adult workers is selected, what is the probability that 5 or more of them have a high school diploma? (That is, find P(X ≥ 5) (round to 4 decimal places) Question 5 of 20 0.0/ 1.0 Points A coin is flipped 30 times. What is the probability of getting 15 or more heads? Round answer to 4 decimal places. 1.0/ 1.0 Points Question 6 of 20 1.0/ 1.0 Points The table of data obtained from WWW.BASEBALL-ALMANAC.COM shows hit information for four well known baseball players. Suppose that one hit from the table is randomly selected. NAME Single Double Triple Home Run TOTAL HITS Babe Ruth 1,517 506 136 714 2,873 Jackie Robinson 1,054 273 54 137 1,518 Ty Cobb 3,603 174 295 114 4,189 Hank Aaron 2,294 624 98 755 3,771 TOTALS 8,468 1,577 583 1,720 12,351 Find P(hit was made by Babe Ruth|The hit was a Triple). • A. 0.066 • B. 0.233 • C. 0.009 • D. .767 1.0/ 3.0 Points Question 7 of 20 0.0/ 1.0 Points An experiment is to flip a fair coin three times. What is the probability of getting exactly two heads? Round to 3 decimal places. Question 8 of 20 1.0/ 1.0 Points In a box there are 4 red cards and 7 blue cards. The cards are well-shuffled. If you pick a card without looking at the box, what is the probability that you pick a blue card? (round to 3 decimal places) Question 9 of 20 0.0/ 1.0 Points Find the probability of rolling a sum of two dice that is more than 7. Round answer to 4 decimal places. 0.0/ 4.0 Points Question 10 of 20 0.0/ 1.0 Points The random variable X = the number of vehicles owned. Find the probability that a person owns at least 2 vehicles. Round to two decimal places. x 0 1 2 3 4 P(X=x) 0.1 0.35 0.25 0.2 0.1 Question 11 of 20 0.0/ 1.0 Points Does the following table represent a valid discrete probability distribution? x 1 2 3 4 5 P(X=x) 0.11 0.06 0.18 0.06 0.59 • A. yes • B. no Q 0.0/ 1.0 Points A company wants to evaluate its attrition rate, in other words, how long new hires stay with the company. Over the years, they have established the following probability distribution. Let X = the number of years a new hire will stay with the company. Let P(x) = the probability that a new hire will stay with the company x years. 1. Complete Table using the data provided. Round to two decimal places. x P(x) 0 0.12 1 0.18 2 0.30 3 0.15 4 0.13 5 0.10 6 0.05 Question 13 of 20 0.0/ 1.0 Points The random variable X = the number of vehicles owned. Find the standard deviation of the number of vehicles owned. Round answer to 4 decimal places. X 0 1 2 3 4 P(X) 0.1 0.35 0.25 0.2 0.1 Part 5 of 6 - Poisson Distribution 5.0/ 5.0 Points Question 14 of 20 1.0/ 1.0 Points The number of rescue calls received by a rescue squad in a city follows a Poisson distribution with an average of 2.83 rescues every eight hours. What is the probability that the squad will have exactly 4 calls in two hours? Round answer to 4 decimal places. Answer: 0.0051 Question 15 of 20 1.0/ 1.0 Points A bank gets an average of 12 customers per hour. Assume the variable follows a Poisson distribution. Find the probability that there will be 4 or more customers at this bank in one hour. (That is, find P(X≥4)) (round to 4 decimal places) Answer: 0.9977 Question 16 of 20 1.0/ 1.0 Points The mean number of visitors at a national park in one weekend is 55. Assume the variable follows a Poisson distribution. Find the probability that there will be at most 71 visitors at this park in one weekend. (That is, find P(X≤71) (round to 4 decimal places) Answer: .9841 Question 17 of 20 1.0/ 1.0 Points Suppose a random variable, x, follows a Poisson distribution. Let µ=2.5 every minute, find the P(X=125) over an hour. Round answer to 4 decimal places. Answer: .0039 Question 18 of 20 1.0/ 1.0 Points A bank gets an average of 8.5 customers per hour. Assume the variable follows a Poisson distribution. Find the probability that there will be 4 or more customers at this bank in one hour. (That is, find P(X≥4) (round to 4 decimal places) Answer: 0.9699 Part 6 of 6 - Probability 2.0/ 2.0 Points Question 19 of 20 1.0/ 1.0 Points If A and B are any two events with P(A) = .8 and P(B|A) = .4, then the joint probability of A and B is: • A. 0.80 • B. 0.40 • C. 0.32 • D. 1.20 Question 20 of 20 1.0/ 1.0 Points If a menu has a choice of 5 appetizers, 4 main courses, and 2 desserts, then the sample space for all possible dinners has how many outcomes? • A. 28 • B. 11 • C. 40 • D. 48 [Show More]

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