# 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 523606: Find the lower limit on a 95% confidence interval for the height of men in the U. S. (Consider each man a sample of size 1.) Mean = 70.21 inches Std. Dev. = 1.02 inches Click here to see answer by stanbon(57361)

 Question 523612: Given that P(A) = 0.4, P(B) = 0.5, and P(A and B) = 0.20, determine P(A|B) Click here to see answer by stanbon(57361)

 Question 523669: patty wack had \$900. She invested part of her savings at 12% and the rest at 9%. If her total annual return was \$96, how much did she invest at each rate? at 12%; at 9% How do you set up the equation? {{.12x+.09(900-x)=96}} Click here to see answer by scott8148(6628)

 Question 523364: plzz help question :the following data represent number of listeners (in thousands) of 15 radio stations in the 6 :00 to 9:00 am time alot in pittsburgh.. a.mean b.median. c.mode. d.midrange. e.range. f.variance g.standard deviation Click here to see answer by richard1234(5390)

 Question 523759: The amounts of money requested in home loan applications at the federal savings are approximately normally distributed with a mean of \$70000 and a standard deviation of \$20000. a loan application is received. what is the probability that: 1. the amount requested is \$80 000 or more 2. twenty percent of the loans are larger than what amount 1 have tried to work the first question 80000 - 70000 / 20000 = 0,05 = 0.5 - 0,05 = 1.65 am stuck Click here to see answer by stanbon(57361)

 Question 523806: You are a researcher who administered a self-esteem measure to 100 participants. The mean self-esteem score for your sample is 52.45 and the standard deviation of the population is 6.28. What is the 90 % confidence interval? Click here to see answer by edjones(7569)

 Question 523757: Give probabilities for the following age :.....<20....20-40.....>40(age group) male:.....168....340.......170 female:...208....290.......160 1.Using the relative frequency of occurrence approach, what is the probability that a customer is a male? 2.What is the probability that a customer is 20 – 40 years old? 3.What is the joint probability of a customer being 20 – 40 years old and a male? 4.Calculate the probability that a customer selected from the male customers would be less than 20 years old. Calculate the same for the female customers. Does it appear that gender is independent of age? Support your answer with calculations and reasons. Click here to see answer by stanbon(57361)

 Question 523819: hello I have some question and I need the answers today because I have an assignment Q1: This homework question: When a pizza restaurant's delivery process is operating effectively When a pizza restaurant's delivery process is operating effectively, pizzas are delivered in an average of 45 minutes with a standard deviation of 6 minutes. To monitor its delivery process, the restaurant randomly selects five pizzas each night and records their delivery times. a. For the sake of argument, assume that the population of all delivery times on a given evening is normally distributed with a mean of  = 45 minutes and a standard deviation of = 6 minutes. (That is we assume that the delivery process is operating effectively) a. Find the mean of the population of all possible sample means and the standard deviation of the population of all possible sample means and Calculate an interval containing 99.73% of all possible sample means. b. Suppose that the mean of the five sampled delivery times on a particular evening is x� = 55 minutes. Using the interval that was calculated in a(4), what would you conclude about whether the restaurant's delivery process is operating effectively? Why? Q2: Quality Progress, February 2005, reports on improvements in customer satisfaction and loyalty made by Bank of America. A key measure of customer satisfaction is the response (on a scale from 1 to 10) to the question: “Considering all the business you do with Bank of America, what is your overall satisfaction with Bank of America?” Here, a response of 9 or 10 represents “customer delight.” Historically, the percentage of Bank of America customers expressing customer delight has been 48%. Suppose that we wish to use the results of a survey of 350 Bank of America customers to justify the claim that more than 48% of all current Bank of America customers would express customer delight. The survey finds that 189 of 350 randomly selected Bank of America customers express customer delight. If, for the sake of argument, we assume that the proportion of customer delight is p = .48, calculate the probability of observing a sample proportion greater than or equal to 189/350 = .54. Click here to see answer by stanbon(57361)

 Question 523752: For a certain binary communication channel the probability that a transmitted '0' is received as '0' is 0.95 and the '1' is 0.90. if the probability that a '0' is transmitted is 0.4, find the probability that a '1' is received and a '1' is transmitted given that a '1' is received Click here to see answer by edjones(7569)

 Question 523793: 4. Research on new juvenile delinquents revealed that 38% of them committed another crime. a. What is the probability that of the last 100 new juvenile delinquents put on probation, 30 or more will commit another crime? b. What is the probability that 40 or fewer of the delinquents will commit another crime? c. What is the probability that between 30 and 40 of the delinquents will commit another crime? Click here to see answer by edjones(7569)

 Question 523868: For each question on a multiple choice test, there are 5 possible answers of which exactly one is correct. If a student selects answers at random, give the probability that the first question answered correctly is question 4. Click here to see answer by stanbon(57361)

 Question 523870: If i have a 1 in 35.1 chance of winning off one powerball ticket. What is the probability that i would win something if i bought 10 tickets? Click here to see answer by stanbon(57361)

 Question 523804: The SAT Quantitative Test has a population mean of 500 and a population standard deviation of 100. Suppose you randomly select a sample of 25 participants and administer the SAT Quantitative Test to each participant. a. What would you expect the mean of this sample to be? _________________ b. What is the standard error of the mean for samples of size 25 from this population? ____________________ c. What is the probability that this sample will be one of the samples that will have a mean SAT Quantitative score greater than 530? ____________________ d. What is the probability that this sample will be one of the samples that will have a mean SAT Quantitative score less than 480? ____________________ e. What is the probability that this sample will be one of the samples that will have a mean SAT Quantitative score between 485 and 525? _____________________ f. Suppose we obtain a mean SAT Quantitative Score of 515. What is the 95% confidence interval for these data? _____________________ g. Supposed we obtain a mean SAT Quantitative Score of 487. What is the 80% confidence interval for these data? Click here to see answer by stanbon(57361)

 Question 523943: 60% of a particular college population are female. What is the probability that of 15 students 5 are female? Click here to see answer by edjones(7569)

 Question 523966: A stick of Length L is broken at a random point that is equally likely along the length of the stick. What is the probability that the longer piece is more than twice as long as the shorter piece? Click here to see answer by edjones(7569)

 Question 523940: A combination lock has a total of 50 numbers and will unlock with the proper 4-number sequence. how many possible combinations exist? Click here to see answer by edjones(7569)

 Question 523939: A multiple choice test has 10 questions,with each question having 4 choices. What is the probability that a student, who randomly answers each question, will answer each question correctly? Click here to see answer by edjones(7569)

 Question 523930: There are 20 people attending an event. A door prize is awarded to attendees if they choose the same number as you randomly pick. Numbers include 1,2,3,4,5. How many prizes should you expect to be won? How many prizes do you need to be 93% confident you have enough for all winners? My attempt. I'm pretty sure the number randomly picked would be µ = 3. Can I say that 1/4 people will pick each of the 5 numbers? So 4 people would choose 3 as their number. Therefore, I would expect 4 people to win. I am lost on the confident part. We have not gone over that yet. Click here to see answer by edjones(7569)

 Question 523984: Two of the integers {1, 3, 4, 5} are chosen at random without replacement. Let X denote the sum. a) List distinct values of X and their probabilities. b) Find expectation of X c) Find standard deviation of X Click here to see answer by edjones(7569)

 Question 524111: I'm not exactly sure where to go on this math problem but this is what is required: Construct a spinner with three regions A, B, and C, but such that you would expect P (e) (A) = 1/2, P(e)(B)=1/3, and P(e)(C)=1/6 on, say, 18 spins. What size angles determine the regions A, B, and C? Any help would be appreciated because I'm just not sure where to start with this question. Click here to see answer by stanbon(57361)

 Question 524118: A pair of dice is rolled, and the number that appears uppermost on each die is observed. Refer to this experiment and find the probability of the given event. The sum of the numbers is an odd number. Click here to see answer by Edwin McCravy(8909)

 Question 524138: A pair of dice is rolled, and the number that appears uppermost on each die is observed. Refer to this experiment and find the probability of the given event. The sum of the numbers is an odd number. Click here to see answer by oberobic(2304)

 Question 524150: You have a bag containing the following marbles: 2 red 3 blue 5 green Compute the probability of the following: 1. Pulling a red marble 2. Pulling a blue marble 3. Pulling a green marble 4. Pulling a red marble OR a green marble 5. Pulling a red marble, putting it back, AND then pulling a green marble 6. Pulling a green marble, putting it back, AND then pulling a green marble 7. Pulling a red marble THEN a blue marble 8. Pulling a blue marble THEN a blue marble 9. Pulling both red marbles 10. P(red OR blue) Click here to see answer by solver91311(16897)

 Question 524152: Hello, Can you please show me how to do this problem? A baseball manager has 12 players of the same ability. How many 9 player starting lineups can he create? Thank You! Click here to see answer by stanbon(57361)
 Question 524152: Hello, Can you please show me how to do this problem? A baseball manager has 12 players of the same ability. How many 9 player starting lineups can he create? Thank You! Click here to see answer by oberobic(2304)

 Question 524116: Let X denote the random variable that gives the sum of the faces that fall uppermost when two fair dice are rolled. Find P(X = 4). (Round your answer to two decimal places.) Click here to see answer by solver91311(16897)

 Question 524173: A pair of dice is rolled, and the number that appears uppermost on each die is observed. Refer to this experiment and find the probability of the given event. One die shows a 6, and the other is a number less than 4. Click here to see answer by stanbon(57361)

 Question 524122: Consider a binomial distribution random variable X with 20 trials (n=20) and p=0.45 (the probability of sucess). What is the average? Click here to see answer by stanbon(57361)

 Question 524139: Among 500 freshmen pursuing a business degree at a university, 332 are enrolled in an economics course, 223 are enrolled in a mathematics course, and 144 are enrolled in both an economics and a mathematics course. What is the probability that a freshman selected at random from this group is enrolled in: (a) An economics and/or a mathematics course? (b) Exactly one of these two courses? (c) Neither an economics course nor a mathematics course? Click here to see answer by solver91311(16897)

 Question 524237: There is a fraternity of 18 students. In how many ways can a committee of 6 be selected? Click here to see answer by Maths68(1474)

 Question 524239: When a pizza restaurant’s delivery process is operating effectively, pizzas are delivered in an average of 45 minutes with a standard deviation of 6 minutes. To monitor its delivery process, the restaurant randomly selects five pizzas each night and records their delivery times. a. For the sake of argument, assume that the population of all delivery times on a given evening is normally distributed with a mean of  = 45 minutes and a standard deviation of = 6 minutes. (That is we assume that the delivery process is operating effectively) 1. Describe the shape of the population of all possible sample means. How do you know what the shape is? 2. Find the mean of the population of all possible sample means. 3. Find the standard deviation of the population of all possible sample means 4. Calculate an interval containing 99.73% of all possible sample means. b. Suppose that the mean of the five sampled delivery times on a particular evening is x¯ = 55 minutes. Using the interval that was calculated in a(4), what would you conclude about whether the restaurant’s delivery process is operating effectively? Why? Click here to see answer by stanbon(57361)

 Question 524449: A local park rents cabins for people who want to vacation by the forest. The fee for the rental is \$27 per night. There is also a \$55 cleaning and maintenance charge that is added to the total bill\$ Click here to see answer by solver91311(16897)

 Question 524464: There are 10 marbles in a bag, 5 are yellow 2 are blue and 3 are green what is the probability of choosing a yellow and a blue marble Click here to see answer by stanbon(57361)

 Question 524473: An accerlerated life test on a large number type-D alkaline batteries revealed that the mean life for a particular use before they failed is 19.0 hours. The distribution of the lives approximated a normal distriburtion. The standard deviation of the distribtuion was 1.2 hours About 95% of the batteries failed between what two values? Click here to see answer by stanbon(57361)

 Question 524470: A jewelery supplier has a supply of earrings which are 30% platinum. A store woner orders five sets of earrings from the supplier. If the supplier selects that paries of earrings at random, what is the chance that the jewelery store gets exacltly two sets of platinum pairs? Click here to see answer by stanbon(57361)

 Question 524466: a student takes a 4 question multiple choice quiz with 4 choices for each question. IF the student guesses at random on each question, what is the probability that the student gets exactly two quesions right? Click here to see answer by stanbon(57361)

 Question 524743: What is the probability of a couple having four children, all of which are girls? Click here to see answer by stanbon(57361)