# Questions on Algebra: Probability and statistics answered by real tutors!

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 Algebra: Probability and statistics Solvers Lessons Answers archive Quiz In Depth

 Question 505958: A company insures a coin collection worth \$20,000 for an annual premium of \$300. There is a .002 chance the collection will be stolen. What is the company's expected profit? Click here to see answer by stanbon(57261)

 Question 505925: If 80% of the applicants are able to pass a driver's proficiency road test, find the mean, variance, and standard deviation of the number of people who pass the test in a sample of 300 applicants. Click here to see answer by stanbon(57261)

 Question 505864: The probability that a PC and a printer function without fail for the first year of guarantee is 0,95 and 0,60 respectively. Assuming the probabilities are independent, calculate the probability that within the year only one of them breaks down. Click here to see answer by stanbon(57261)

 Question 506091: There are 15 cards, numbered 1 through 15. If you pick a card, what is the probability that you choose an odd number or a two? Click here to see answer by stanbon(57261)

 Question 506071: a multiple choice test allows answers of a,b,c,d,e for each question. A student will answer ten questions by making random guesses. what is the probability that he will get the first answer correct? Click here to see answer by stanbon(57261)

 Question 506066: a bicycle combination consists of 3 numbers choosen in sequence. the numbers available are 1-5 and cannot be repeated. if a person guesses randomly for the 3 digit combination what is the probability he guesses correctly? Click here to see answer by stanbon(57261)

 Question 506048: You roll two fair dice, a green one and a red one. (Round your answers to three decimal places.) What is the probability of getting a sum of 11? Click here to see answer by stanbon(57261)

 Question 506038: This problem has me confused. I have tried using the Ztest and even Chi Sq but cannot determine how to compute using 2 standard deviations. Thanks in advance. A lab technician is tested for her consistency by taking multiple measurements of cholesterol levels from the same blood sample. The target accuracy is a standard deviation of 1.2 or less. If 20 measurements are taken and their standard deviation is 1.8, is there enough evidence to reject the claim that her standard deviation is within the limit at  a= .01? A) No, comparing the test value 45.00 and the critical value 37.566. B) Yes, comparing the test value 42.75 and the critical value 36.191. C) Yes, comparing the test value 45.00 and the critical value 37.566. D) No, comparing the test value 42.75 and the critical value 36.191. Click here to see answer by stanbon(57261)

 Question 506207: each of the four engines on an airplane functions correctly on a given flight with probability .99., and the engines function independently of each other. Assume that the plane can make a safe landing if at least two engines are functioning correctly. What is the probability the engines will allow the plane to land safely. Click here to see answer by stanbon(57261)

 Question 506226: A manufacturer found that among 500 randomly selected smoke detectors only 450 worked properly. Based on this information, how many smoke detectors would you have to install to be sure that the probability that at least one of them will work will be at least 99.99% Click here to see answer by stanbon(57261)

 Question 506299: three members will randomly be selected from seven candidates. A)how many different outcomes are there-is it 7C3? B)what is probability of selecting the tallest members? Click here to see answer by stanbon(57261)

 Question 506314: The following time series data represent the yearly amounts spent on advertising (in millions of dollars) by a large toy company: 21.5, 24.2, 23.7, 24.8, 25.7 This series of data begins in year (i.e., time period corresponds to ). Using regression analysis, a linear trend line of the form was fit to the data. Using this information, generate a forecast for the total yearly amount of money that will be spent on advertising in . Click here to see answer by stanbon(57261)

 Question 506351: The Census Bureau reports that 82% of Americans over the age of 25 are high school graduates. A survey of randomly selected residents of certain county included 1260 who were over the age of 25, and 1035 of them were high school graduates. (a) Find the mean and standard deviation for the number of high school graduates in groups of 1260 Americans over the age of 25. Mean = Standard deviation = Is that county result of 1035 unusually high, or low, or neither? Click here to see answer by stanbon(57261)

 Question 506454: 35% of American households subscribe to TIVO. Suppose that 12 American households are randomly chosen. a) How many of them would you expect to have TIVO? I got 4.2.. do you round to 4 because they are people? b) What is the probability that 2 OR 3 of them have TIVO? I don't know where to begin... Click here to see answer by xdragonfight(116)

 Question 506461: 48.7% of Americans have brown eyes. A convention has 5000 people in attendance. Find the mean (expected value),the standard deviation, and the variance for the number of brown-eyed people at such gatherings of 5000 people. Click here to see answer by xdragonfight(116)

 Question 506462: A recent survey shows that 70% of families regularly schedule family vacations for the month of April. Find the probability that at least 10 out of 15 randomly selected families regularly schedule family vacations for the month of April. Click here to see answer by xdragonfight(116)

 Question 506460: Type O blood is found in 44% of Americans. Suppose 7 samples of blood are tested at random. Find the probability that exactly 2 of the tested samples will be Type O. Click here to see answer by xdragonfight(116)

 Question 506712: A survey found that 40% of all teens get their spending money from part time jobs. In a group of 7 randomly selected teens, what is the probability 4 get their money from part time job. Click here to see answer by stanbon(57261)

 Question 506626: Several students are unpreapred for a surprise true/false test with 9 questions and all of their answers are guesses. Find the mean and standard deviation for the number of correct answers. Would it be unusual for a student to p[ass by guessing and getting at least 4 correct answers? Click here to see answer by stanbon(57261)

 Question 507007: The number of accidents per week at a hazardous intersection varies with mean 2 and standard deviation 1.8. This distribution takes only whole-number values, so it is certainly not Normal. Let be the mean number of accidents per week at the intersection during a year (52 weeks). What is the approximate mean (±0.1) of according to the central limit theorem? Click here to see answer by stanbon(57261)

 Question 506941: there is a .35 percent chance that if you take pill x, you will get insomnia. What is the probability that at least five will experience insomnia out of a sample of 25? Click here to see answer by stanbon(57261)

 Question 506911: Tim discovered that 2 out of every 45 toy trucks made at the county toy factory is broken. On a large order of 180 trucks, how many broken trucks can Tim likely expect to find? Click here to see answer by stanbon(57261)

 Question 506904: 8.64 Biting an unpopped kernel of popcorn hurts! As an experiment, a self-confessed connoisseur of cheap popcorn carefully counted 773 kernels and put them in a popper. After popping, the unpopped kernels were counted. There were 86. (a) Construct a 90 percent confidence interval for the proportion of all kernels that would not pop. (b) Check the normality assumption. (c) Try the Very Quick Rule. Does it work well here? Why, or why not? (d) Why might this sample not be typical? Click here to see answer by stanbon(57261)

 Question 506865: Given: Set U is {s,o,p,h,I,a}. Set B is {a,l,o}. If set B is a subset of set U, what is the complement of set B? Click here to see answer by stanbon(57261)

 Question 507054: For the table that follows, answer the following question. x....y 1....1 2....4 3....7 4.... Would the correlation between x and y in the table above be positive or negative? Find the missing value of y in the table. How would the values of this table be interpreted in terms of linear regression? If a "line of best fit" is placed among these points plotted on a coordinate system, would the slope of this line be positive or negative? Click here to see answer by stanbon(57261)

 Question 507157: . The numbers 2,3,5,6, and 8 are written on five cards and these are placed on a table. Two of these cards are selected at random to form a two digit number. List the sample space and find the probability that the number formed is (i) odd, (ii) divisible by 7, (iii) prime, (iv) greater than 54. Click here to see answer by Edwin McCravy(8883)

 Question 507155: The numbers 2,3,5,6, and 8 are written on five cards and these are placed on a table. Two of these cards are selected at random to form a two digit number. List the sample space and find the probability that the number formed is (i) odd, (ii) divisible by 7, (iii) prime, (iv) greater than 54. Click here to see answer by Edwin McCravy(8883)

 Question 507158: If the probability of balls is 5/9 and there are 45 balls comprising of white and red balls, Find the number that is red. Click here to see answer by stanbon(57261)

 Question 507142: Out of 100 jobs vacant at some software company, 30 jobs are class I and 70 jobs are class II. Sample of 30 jobs are taken, then find the probability that a) There will be exactly 12 jobs of class I b) At the most 2 jobs on class II Click here to see answer by stanbon(57261)

 Question 507135: how many subsets of 6 are there in numbers 1 to 55 Click here to see answer by Edwin McCravy(8883)

 Question 507134: how many of subset of 6 are there in number 1 to 42 Click here to see answer by Edwin McCravy(8883)

 Question 507184: In a gambling game a man is paid \$3 if he draws a jack or queen and \$5 if he draws a king or ace from an ordinary deck of 52 playing cards. If he draws any other card, he looses. How much should he pay to play if the game is fair? Click here to see answer by Edwin McCravy(8883)

 Question 507200: If 80% of the applicants are able to pass a driver's proficiency road test, find the mean, variance and standard deviation of the number of people who pass the test in a sample of 300? Click here to see answer by richard1234(5390)

 Question 507234: How can an employer give four different pairs of shoes to four employees out of 15 employees? Is is C(15,4)? Thank you. Click here to see answer by Edwin McCravy(8883)
 Question 507234: How can an employer give four different pairs of shoes to four employees out of 15 employees? Is is C(15,4)? Thank you. Click here to see answer by richard1234(5390)

 Question 507256: A shipment of 9 typewriters contains 3 that are defective.Find the probability that a sample of size four, drawn from the nine, will not contain a defective typewriter. Click here to see answer by stanbon(57261)

 Question 507249: The instructor in a humanities class says that students have a 15% probability of making an A in her class, 20% probability of making a B, 25% chance of making a C, 20% of making a D, and 5% of making a F. The possible grades are A,B,C,D,F and N. What is the probability that a randomly selected student will make a passing grade, that is an A,B, or C? A. 30% B. 33% C. 50% D Cannot be determined from the information given. Click here to see answer by stanbon(57261)

 Question 507366: 4. A division has 12 employees, 8 males and 4 females. (a) How many ways can a committee of 6 members can be selected from out of these 12? (b) Find the probability that the committee contains all males? (c) How many ways can they choose a President of the committee, if the President has to be a female and the other officers must be males? Click here to see answer by stanbon(57261)

 Question 507215: when the mean is 300 and the standard deviation is 20 can the z score be a negative number? thank you Click here to see answer by stanbon(57261)

 Question 507360: Among students 70% own a car, 50% own a bike and 40% own both. (a) Find a probability that a randomly chosen student own a least one of the above vehicles. (b) What is a probability that a randomly chosen student does not own a bike? Click here to see answer by stanbon(57261)

 Question 507367: 7. Among companies doing highway or bridge construction, 80% test employees for substance abuse (based on data from the Construction Financial Management Association) A study involves the random selection of 12 such companies. (a) Find the probability that exactly 7 of the 12 companies test for substance abuse. (b) Find the probability that at least half of the companies test for substance abuse. (c) For such group of 12 companies, find the mean and standard deviation for the number (among 12) that test for substance abuse. (d) Using the results from part (c) and the range rule of thumb, indentify the range of usual value. Click here to see answer by stanbon(57261)

 Question 507246: Five balls are selected at random without replacement from an urn containing three white balls and five blue balls. Find the probability that two or three of the balls are white. The "two OR three of the balls are white" is confusing me! Click here to see answer by stanbon(57261)

 Question 507431: use the given confidence interval limits to find the point estimate and the margin of error Click here to see answer by richard1234(5390)

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