# 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 135432: The number of passengers on the Carnival Sensation during one-week cruises in the Caribbean follows the normal distribution. The mean number of passengers per cruise is 1,820 and the standard deviation is 120. a.What percent of the cruises will have between 1,820 and 1,970 passengers? b. What percent of the cruises will have 1,970 passengers or more? c. What percent of the cruises will have 1,600 or fewer passengers? d. How many passengers are on the cruises with the fewest 25 percent of passengers? Click here to see answer by stanbon(57967)

 Question 135431: The accounting department at Weston Materials, Inc., a national manufacturer of unattached garages, reports that it takes two construction workers a mean of 32 hours and a standard deviation of 2 hours to erect the Red Barn model.Assume the assembly times follow the normal distribution. a. Determine the z values for 29 and 34 hours. What percent of the garages take between 32 hours and 34 hours to erect? b.What percent of the garages take between 29 hours and 34 hours to erect? c. What percent of the garages take 28.7 hours or less to erect? d. Of the garages, 5 percent take how many hours or more to erect? Click here to see answer by stanbon(57967)

 Question 135428: The weights (in pounds) of a sample of five boxes being sent by UPS are: 12, 6, 7, 3, and 10. Compute the range. Compute the mean deviation. Compute the standard deviation. Click here to see answer by stanbon(57967)

 Question 135604: A coin was flipped 60 times and came up heads 38 times. (a) At the .10 level of significance, is the coin biased toward heads? Show your decision rule and calculations. (b) Calculate a p-value and interpret it. Click here to see answer by stanbon(57967)

 Question 135627: In a Box I have (2 red balls, 3 white balls, and 5 green balls). What is the probability of picking the same color twice? Please show me how to calculate this. Click here to see answer by stanbon(57967)

 Question 135683: I would like to know what the probability of taking three cards from a full deck of cards and having at least one jack,queen or king in the three cards. I have been told that the answer is 12/52 X 12/51 X 12/50 or about 70% and I feel that this is wrong. Please advise how to figure this out. Thank you. Click here to see answer by stanbon(57967)
 Question 135683: I would like to know what the probability of taking three cards from a full deck of cards and having at least one jack,queen or king in the three cards. I have been told that the answer is 12/52 X 12/51 X 12/50 or about 70% and I feel that this is wrong. Please advise how to figure this out. Thank you. Click here to see answer by solver91311(17077)

 Question 135687: I would like to know what the probability of taking three cards from a full deck of cards and having at least one jack,queen or king in the three cards. I have been told that the answer is 12/52 X 12/51 X 12/50 or about 70% and I feel that this is wrong. Please advise how to figure this out. Thank you. Click here to see answer by solver91311(17077)

 Question 135710: jennifer has 8 blue marbles, 12 orange marbles, & 10 red marbles What is the probability of picking an orange marble. Predict the number of times out of 120 Jennifer will pick an orange marble. Please help to explain so we can show the work. Click here to see answer by vleith(2825)
 Question 135710: jennifer has 8 blue marbles, 12 orange marbles, & 10 red marbles What is the probability of picking an orange marble. Predict the number of times out of 120 Jennifer will pick an orange marble. Please help to explain so we can show the work. Click here to see answer by solver91311(17077)

 Question 135763: The following data give the annual production of wheat in lack tons in Faisalabad. Fit a straight line with the help of least squares method and find the trend value for year too. Year 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 Pro 3.6 4.3 5.6 6.2 6.6 5.0 6.3 6.5 6.3 6.4 Click here to see answer by stanbon(57967)

 Question 135744: I'm in an online class so there is no textbook, please help, thanks. A sample of 25 concession stand purchases at the October 22 matinee of Bride of Chucky showed a mean purchase of \$5.29 with a standard deviation of \$3.02. For the October 26 evening showing of the same movie, for a sample of 25 purchases the mean was \$5.12 with a standard deviation of \$2.14. The means appear to be very close, but not the variances. At α = .05, is there a difference in variances? Show all steps clearly, including an illustration of the decision rule. Click here to see answer by stanbon(57967)

 Question 135786: A sample of 20 pages was taken without replacement from the 1,591-page phone directory Ameritech Pages Plus Yellow Pages. On each page, the mean area devoted to display ads was measured (a display ad is a large block of multicolored illustrations, maps, and text). The data (in square millimeters) are shown below: 0 260 356 403 536 0 268 369 428 536 268 396 469 536 162 338 403 536 536 130 (a) Construct a 95 percent confidence interval for the true mean. (b) Why might normality be an issue here? (c) What sample size would be needed to obtain an error of ±10 square millimeters with 99 percent confidence? (d) If this is not a reasonable requirement, suggest one that is. Click here to see answer by stanbon(57967)

 Question 135790: A pizza parlor has a choice of 12 toppings for its pizzas. From these 12toppings, how many different 4-topping pizzas can be ordered? Assume that the order in which the toppings are listed does not matter. Click here to see answer by stanbon(57967)

 Question 135869: Find the value of the following: 7!12! _____ 10!11! If your answer is not an integer, write it as an exact fraction. Click here to see answer by solver91311(17077)

 Question 135910: I need help on this question this is part of a test. Does not show the text book instructor used. 3. An engineer in a widget factory wants to make a change to the process, and to switch to a cheaper supplier of the crucial raw material in the manufacture of widgets (that is, of course, widgeterium). It is important that the weight of the finished widgets not be different from the specified weight of 10 grams. A sample of 40 widgets created on a test run of the new material has an average weight of 10.8 grams, with a standard deviation of 2. Show work a. Identify the null and alternative hypothesis b. Calculate the proper test statistic c. Calculate the proper P-value d. In plain English, properly interpret the results, using a significance level of 0.05. Click here to see answer by stanbon(57967)

 Question 135787: A careful count of 13,789 carcasses of bugs killed by “mosquito zappers” used in homes near water showed that only 18 were mosquitoes. (a) Construct a 90 percent confidence interval for the proportion of all zapped bugs that are mosquitoes. (b) Is a confidence interval really helpful in deciding whether the devices fulfill their purpose? Explain Click here to see answer by stanbon(57967)

 Question 135937: A coin-operated coffee machine made by BIG Corporation was designed to discharge a mean of eight ounces of coffee per cup. If it dispenses more that that on average, the corporation may lose money, and if it dispenses less, the customers may complain. BIG Corporation would like to estimate the mean amount of coffee, , dispensed per cup by this machine. BIG will choose a random sample of cup amounts dispensed by this machine and use this sample to estimate . Assuming that the standard deviation of cup amounts dispensed by this machine is 0.42 ounces, what is the minimum sample size needed in order for BIG to be 90% confident that its estimate is within 0.08 ounces of ? Carry your intermediate computations to at least three decimal places. Write your answer as a whole number (and make sure that it is the minimum whole number that satisfies the requirements). Click here to see answer by stanbon(57967)

 Question 135935: The lifetime of a certain brand of battery is known to have a standard deviation of 9 hours. Suppose that a random sample of 100 such batteries has a mean lifetime of 45.6 hours. Based on this sample, find a 95% confidence interval for the true mean lifetime of all batteries of this brand. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. What is the lower limit of 95% confindence interval? What is the upper limit of 95% confindence interval? Click here to see answer by stanbon(57967)

 Question 136008: A menu offers a choice of three salads, eight main dishes and five desserts. How many three course ,meals are possible? Click here to see answer by solver91311(17077)

 Question 136011: when rolling a pair of dice, what is the probability of rolling the sum of six? rolling a pair? Click here to see answer by checkley77(12569)

 Question 136030: A number cube is rolled three times. What is the probability of rolling a 5 at least once? I know that everytime there is a 1 in 6 chance of getting a 5. So in three rolls that would be 3 chances in 18. So to get it at least once-would it be a 1 in 18 chance? Click here to see answer by stanbon(57967)

 Question 136010: in a family of six children, what is the probability of having at least three girls? Click here to see answer by stanbon(57967)

 Question 135954: There are 15 entrees available at a restaurant. From these, Archie is to choose 5 for his party. How many groups of 5 entrees can he choose, assuming that the order of the entrees chosen does not matter? Click here to see answer by stanbon(57967)

 Question 136064: In a class of 30 studnts, there are 17 girls and 13 boys. Five are A students, and three of these students are girls. If a student is chosen at random, what is the probability of choosing a girl and a A student? Click here to see answer by stanbon(57967)

 Question 136091: Find the value of the following: 7!11! ______ 9!8! If your answer is not an integer, write it as an exact fraction. Click here to see answer by oscargut(900)

 Question 136094: Suppose that a researcher is interested in estimating the mean systolic blood pressure, , of executives of major corporations. He plans to use the blood pressures of a random sample of executives of major corporations to estimate . Assuming that the standard deviation of the population of systolic blood pressures of executives of major corporations is26 mm Hg, what is the minimum sample size needed for the researcher to be 99% confident that his estimate is within 6 mm Hg of ? Carry your intermediate computations to at least three decimal places. Write your answer as a whole number (and make sure that it is the minimum whole number that satisfies the requirements). Click here to see answer by stanbon(57967)

 Question 136093: An aptitude test is designed to measure leadership abilities of the test subjects. Suppose that the scores on the test are normally distributed with a mean of 580 and a standard deviation of 125 . The individuals who exceed 780 on this test are considered to be potential leaders. What proportion of the population are considered to be potential leaders? Round your answer to at least four decimal places. Click here to see answer by stanbon(57967)

 Question 136092: There are 14 entrees available at a restaurant. From these, Archie is to choose 5 for his party. How many groups of entrees can he choose, assuming that the order of the entrees chosen does not matter? Click here to see answer by stanbon(57967)

 Question 136133: Given P(A),find P (not A) Events A and B are dependent.P(A) = 5/12 and P(B given A) = 6/11. Find (A and B) Thank You for the straightfoward and correct answers you all send me. Click here to see answer by vleith(2825)

 Question 136128: Given P(A),find P (not A) P(A)=3/8 Thank You for the straightfoward and correct answers you all send me. Click here to see answer by nycsharkman(136)

 Question 136143: Need help Suppose that the heights of adult women in the United States are normally distributed with a mean of 63.5 inches and a standard deviation of 2.4 inches. Jennifer is taller than 90% of the population of U.S. women. How tall (in inches) is Jennifer? Carry your intermediate computations to at least four decimal places. Round your answer to at least one decimal place. Inches = Click here to see answer by vleith(2825)

 Question 136130: Given P(A),find P (not A) P(A)=0.37 Thank You for the straightfoward and correct answers you all send me. Click here to see answer by nycsharkman(136)

 Question 136125: Given P(A),find P(not A). P(A)=98% Thank You for the straightfoward and correct answers you all send me. Click here to see answer by nycsharkman(136)

 Question 136124: Events A and B are disjoint. P(A) = 40/61 and P(B) = 2/61 Find P(A or B). Thank You for the straightfoward and correct answers you all send me. Click here to see answer by nycsharkman(136)

 Question 136080: Can someone help me with these 2 problems. My instructor asked this question and I have no clue as to what is going on here. Thanks In Advance. 1. Imagine this scenario at your marketing department .. You have been given the task of showing that there is a difference between gender and potato chip preferences. A colleague has obtained some sample data for you: Lays Jays Better Maid Private Label Male 16 6 5 10 Female 7 4 11 7 >> how will you proceed ?? 2. To test the hypothesis that students who finish an exam first get better grades. Professor Hardtack kept track of the order in which papers were handed in. The first 25 papers showed a mean score of 77.1 with the standard deviation of 19.6, while the last 24 papers handed in showed a mean score of 69.3 with a standard deviation of 24.9. Is this a significant difference at a= .05? (a) State the hypothesis for a right -tailed test. (b) Obtain a test statistic and p-value assuming equal variances. Interprest these results. (c) Is the difference in mean scores large enough to be important> (d) Is it reasonable to assume equal variances? (e) Carry out a formal test for equal variances at a-.05, showing all steps clearly Click here to see answer by stanbon(57967)

 Question 136232: Instructor Dorff wants to test the hypothesis that students who finish an exam earlier .... get a better score. She kept track of the order of the submission of a recent test; >> the first 25 papers showed a mean score of 77.1 with std deviation of 19.6 >> the second 24 papers showed a mean score of 69.3 with std deviation of 24.9 >> state the hypothesis for a right tailed test and test at the 0.05 level of significance .. and determine if the difference in scores is significant Click here to see answer by stanbon(57967)

 Question 136270: a random sample of 10 miniature tootsie rolls was taken from a bag. each piece was weighed on a very accurate scale: the results in grams were 3.087 3.131 3.241 3.241 3.270 3.353 3.400 3.411 3.437 3.477 construct a 90 percent confidence interval for the true mean weight. what sample size would be necessary to estimate the true weight with an error of + 0.03 grams with 90 percent confidence? Click here to see answer by stanbon(57967)

 Question 136327: A college baseball coach read in a sports magazine that the average fastball speed of all the pitchers who competed last year in the college world series was 90.4 mph. The 16 pitchers who tried out for the school’s team this year averaged 88.2 mph, and the standard deviation was 3.4 mph. What is the value of the test statistic? a. –25.9 b. –0.65 c. –2.59 d. 0.65 Click here to see answer by stanbon(57967)

 Question 136326: The e-mail usage for two different plants of a large company was compared at level of significance 0.05. Samples of ten employees were selected at each plant. The mean number of e-mail messages sent per employee for one plant was 15.5 per week and the standard deviation was 5.0. For the other plant, the mean was 18.4 and the standard deviation was 1.6. For the test of equal population means (assuming equal population variances), the degrees of freedom, the absolute value of the computed test statistic, and the critical values for the test statistic respectively are: a. 18, 1.75, ± 2.101 b. 11, 1.75, ± 2.201 c. 18, 1.75, ± 1.96 d. 11, 2.201, ± 1.75 Click here to see answer by stanbon(57967)

 Question 136318: What is the critical F value with a dfn=7 and a dfd=5? Use an alpha of .10 Click here to see answer by stanbon(57967)

 Question 136317: The manufacturer of Advil, a common headache remedy, recently developed a new formulation of the drug that is claimed to be more effective. To evaluate the new drug a sample of 500 current users is asked to try it. After a one month trial, 400 indicated the new drug was more effective in relieving the headache. At the same time, a sample of 350 current Advil users is given the current drug but told it is the new formulation. From this group 300 said it was an improvement. At the .01 significance level can we conclude that the new drug is more effective? Ho H1 Alpha: CV: What Formula? Click here to see answer by stanbon(57967)

 Question 136316: A Cell phone company offers two plans to its subscribers. At the time new subscribers sign up they are asked to provide some demographic information. The mean yearly income for a sample of 42 subscribers to plan A is \$57,000 with a standard Deviation of \$6,000. For a sample of 50 subscribers to plan B the mean income is \$63,000 with a standard deviation of \$4,900. At a significance of 0.05 is there a difference in between the two plans? Ho H1 Alpha: CV: What Formula? Click here to see answer by stanbon(57967)

 Question 136335: Assume the likelihood that any flight on Northwest Airlines arrives within 15 minutes of the scheduled time is 0.90. We select four flights from yesterday for study. (Question 50) a. What is the likelihood all four of the selected flights arrived within 15 minutes of scheduled time? b. What is the likelihood at least one of the selected flights did not arrive within 15 minutes of the scheduled time? c. What is the likelihood that none of the selected flights arrived within 15 minutes of the scheduled time? Click here to see answer by stanbon(57967)

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