# 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 275880: 59. In 1991, students from countries around the world took the International Assessment of Educational Progress test. The following table gives the average mathematics scores for 15 countries, along with the number of days that students in each country spend in school each year. (a) Make a conjecture about the relationship between the World Almanac Books, 2002. country’s mathematics score and the number of days spent in school. (b) Test your conjecture by using a box plot to compare students who spend 190 days or fewer in school with those who spend more than 190 days in school. (c) Explain how your graph supports or disproves your conjecture. Country Days of School Math Score Canada 188 62 France 174 64 Hungary 177 68 Ireland 173 61 Israel 215 63 Italy 204 64 Jordan 191 40 Korea 222 73 Scotland 191 61 Slovenia 190 57 Soviet Union 198 70 Spain 188 55 Switzerland 207 71 Taiwan 222 73 United States 178 55 (d) Draw a scatterplot for the data and see if there seems to be a correlation between mathematics scores and days in school. Is this the same message your box plot gave you? Which plot would you use to support your conjecture Click here to see answer by stanbon(57307)

 Question 275878: in a class of 147 students, 95 are taking math(M) 73 are taking science(S), and 52 are taking both math ans science. one student is picked at random. find p(taking math science or both) and p( not taking math). any help would be great but i would like to understand how to work the problem. if you could give a short explaination( i know thats not spelled right) it would be greatly appreciated. Click here to see answer by stanbon(57307)

 Question 275929: The probability that a small business will go bankrupt in its first year is .21. For 50 such small businesses, find the following probabilities first by using the binomial probability formula, and then by using the normal approximation. a. Exactly 8 go bankrupt. b. No more than 2 go bankrupt. Click here to see answer by stanbon(57307)

 Question 275849: The manufacturer of a new line of ink-jet printers would like to include as part of its advertising the number of pages a user can expect from a print cartridge. A sample of 10 cartridges revealed the following number of pages printed. 2,698 2,028 2,474 2,395 2,372 2,475 1,927 3,006 2,334 2,379 a. What is the point estimate of the population mean? b. Develop a 95 percent confidence interval for the population mean. Click here to see answer by stanbon(57307)

 Question 275739: A spinner has ten equal-size sections numbered from 1 to 10. Find the probability of each event when you spin the spinner. 6. P(even or multiple of 5) 7. P(multiple of 3 or multiple of 4) Click here to see answer by stanbon(57307)

 Question 275730: The Rice is Right is a cooking show that randomly selects participants from the audience to assist the chef (assume the audience consists of 60% women and 40% men). a) what is the probability of getting exactly 10 women out 12 participants? Click here to see answer by stanbon(57307)

 Question 275994: An airline estimates that 91% of people booked on their flights actualy show up. If the arline books 79 people on a flight for which the maximum number is 77, what is the probability that the number of people who show up will exceed the capacity of the plane? Click here to see answer by stanbon(57307)
 Question 275994: An airline estimates that 91% of people booked on their flights actualy show up. If the arline books 79 people on a flight for which the maximum number is 77, what is the probability that the number of people who show up will exceed the capacity of the plane? Click here to see answer by Honey88(1)

 Question 275992: As the new city planner for a developing community you need to project a budget for garbage trucks. To support your numbers you will use an estimate of the mean weight of garbage discarded weekly by household. a. Find the sample size necessary to estimate the mean if you want to be 90% confident that the sample mean is within 2 pounds of the true population mean. A sample of 62 households produced a standard deviation = 12.46 pounds Try it again at a 95% and a 99% confidence and indicate the change in the sample size and why you think this is so. b. Give an example from your workplace of a problem that requires you to determine a sample size. Click here to see answer by stanbon(57307)

 Question 276046: in one city, the probability that a person will pass his or her driving test on the first attempt is 0.61. 11 people are selected at random from among those taking their driving test for the first time. What is the probability that among these 11 people, the number passing the test is between 2 and 4 inclusive? Click here to see answer by stanbon(57307)

 Question 275991: You have measured the temperature of a large number of patients at a local clinic. You find the 95% confidence interval to be 96.7 and 99.1. In another sample of a large number of patients a mistake was made in an entry. a. If instead of an entry of 98.6 an error was made and entered as 9.86, what is the effect on the confidence interval? Explain. b. If instead of an entry of 98.6 an error was made and entered as 986, what is the effect on the confidence interval? Explain. c. What tips you to a confidence interval that needs investigation for error? Click here to see answer by stanbon(57307)

 Question 275990: You are responsible for reliability of the electronic product that your company produces. You decide to measure the time between equipment malfunctions over a one-year period. Over that time you measured 40 electronic products. You made 850 observations with a mean time between equipment failures of 550.35 hours, and a sample standard deviation of 207 hours. Your company supplies the electronic product to another company as a component to their product. You guarantee an average time between malfunctions of 600 or more hours. Calculate a 99% confidence interval estimate for the mean time between malfunctions for all electronics of this type then interpret the results to assess whether your company will have a problem with this guarantee. Explain your reasoning? Click here to see answer by stanbon(57307)

 Question 276086: We roll a pair of dice. If the sum of the dice is 7, you pay \$30. If the sum is not 7, I pay you the number of dollars indicated by the sum of the dice. What is your expected value for the game? Click here to see answer by stanbon(57307)

 Question 276139: Bob is trying to borrow \$1000 from friends. One of every 3 friends asked responds that their money is tied up. Of his friends with money not tied up, 2 out of 5 inform him quickly that they won't lend him money. Of the remainder, 1 out 2 won't lend him money on general principles. If Bob called 60 friends, how many might lend him money? Click here to see answer by vleith(2825)
 Question 276139: Bob is trying to borrow \$1000 from friends. One of every 3 friends asked responds that their money is tied up. Of his friends with money not tied up, 2 out of 5 inform him quickly that they won't lend him money. Of the remainder, 1 out 2 won't lend him money on general principles. If Bob called 60 friends, how many might lend him money? Click here to see answer by solver91311(16877)
 Question 276139: Bob is trying to borrow \$1000 from friends. One of every 3 friends asked responds that their money is tied up. Of his friends with money not tied up, 2 out of 5 inform him quickly that they won't lend him money. Of the remainder, 1 out 2 won't lend him money on general principles. If Bob called 60 friends, how many might lend him money? Click here to see answer by stanbon(57307)

 Question 276160: one number is twice as large as the second. the sum of the numbers is 366. what is the larger number? Click here to see answer by rfer(12657)

 Question 276135: June, marie, and Billy each have a collection of marbles. June has 20 more marbles than Billy, and Maria has 3 times as many marbles as Billy. If altogether they have 100 marbles, how many marbles does Billy have? Click here to see answer by richwmiller(9135)

 Question 276178: Consider a tree diagram representing all the possible final outcomes in the following scenario: You buy a fancy sports car with 7 choices of wheel covers, 4 choices of stereo model, 8 upholstery packages, and a choice of clear or tinted glass windows. How many "leaves" does the tree have? Click here to see answer by checkley77(12569)
 Question 276178: Consider a tree diagram representing all the possible final outcomes in the following scenario: You buy a fancy sports car with 7 choices of wheel covers, 4 choices of stereo model, 8 upholstery packages, and a choice of clear or tinted glass windows. How many "leaves" does the tree have? Click here to see answer by sk8r4life(1)

 Question 276332: Five six-sided dice are rolled. What is the probability that at least one of them will show a 4? Hint: Using the complement may help. Click here to see answer by solver91311(16877)

 Question 276339: A binomial distribution has n=1580 and p=0.798. Find the mean of this distribution to the nearest tenth. Find the variance and standard deviation of this distribution to the nearest hundredth. Find the minimum and maximum usual values of mu +- 2 r Click here to see answer by stanbon(57307)

 Question 276336: Of 1937 people who came into a blood bank to give blood, 679 had high blood pressure. Estimate the probability that the next person who comes in will also have high blood pressure. Thanks Click here to see answer by stanbon(57307)

 Question 276206: On average, 40 percent of US beer drinkers order light beer. a) What is the probability that none of the next eight customers who order beer will order light beer? b) That one customer will? c) Two customers? d) Fewer than three? Click here to see answer by stanbon(57307)

 Question 276369: A student observes the following spinner and claims that the color red has the highest probability of appearing, since there are two red areas on the spinner. What is your reply to the student? The picture of the spinner shows 1/2 green, 1/4 blue, and 2 (1/8 sections) red Click here to see answer by stanbon(57307)

 Question 276372: . In a British study around 1925, a group of 649 men with lung cancer were surveyed. A control group of the same size was established from a set of men who did not have lung cancer. The groups were matched according to ethnicity, age, and socioeconomic status. The statistics from the survey follow. What type/Lung Cancer Cases/Controls/Totals Smokers/647/622/1269 Non-smokers/2/27/29 a. What is the proportion of smoking in the group that has lung cancer in the study? b. What is the proportion of smoking in the control group? c. If one person is chosen at random from each of the two groups, what is the probability that each person chosen has cancer? d. Do you think that this data presents a strong association between lung cancer and smoking? Explain your answer. e. Do you think that this evidence is conclusive that smoking causes lung cancer? Click here to see answer by stanbon(57307)

 Question 276388: A company claims to have invented a hand-held sensor that can detect the presence of explosives inside a closed container. Law enforcement and security agencies are very interested in purchasing several of the devices if they are shown to perform effectively. An independent laboratory arranged a test. They placed four empty boxes in the corners of an otherwise empty room. For each trial they put a small quantity of an explosive in one of the boxes selected at random. The company's technician then entered the room and used the sensor to try to determine which of the four boxes contained the explosive. The experiment consisted of 50 trials, and the technician was successful in finding the explosive 16 times. Does this indicate that the device is effective in sensing the presence of explosives? 1. Test an appropriate hypothesis and state your conclusion. 2. Was your test one-tail lower, or two tail? Explain why you chose that kind of test in this situation. 3. Explain what your P-value means in this context. Click here to see answer by stanbon(57307)

 Question 276399: You are taking a multiple-choice test that has 12 questions. Each of the questions has 5 choices, with one correct choice per question. If you select one of these options per question and leave nothing blank, in how many ways can you answer the questions? The answer is 244,140,625 but why? Click here to see answer by stanbon(57307)
 Question 276399: You are taking a multiple-choice test that has 12 questions. Each of the questions has 5 choices, with one correct choice per question. If you select one of these options per question and leave nothing blank, in how many ways can you answer the questions? The answer is 244,140,625 but why? Click here to see answer by edjones(7569)

 Question 276370: A coin is flipped 3 times and heads (H) or tails (T) are recorded. a. List all three elements in the sample area. b. List the elements in the event "at least two heads appear." c. Find the probability that the event in part (b) occurs. Click here to see answer by stanbon(57307)

 Question 276406: Given that P(A or B) = 1/3, P(A) = 1/6, and P(A and B) = 1/8, find P(B). 7/24 is the answer but I would really love to know why. This question is worded in a very confusing manner. Click here to see answer by stanbon(57307)
 Question 276406: Given that P(A or B) = 1/3, P(A) = 1/6, and P(A and B) = 1/8, find P(B). 7/24 is the answer but I would really love to know why. This question is worded in a very confusing manner. Click here to see answer by edjones(7569)

 Question 276120: many radio ststions in the united states have call letters that begin with a W or a K and have four letters. how many arrangements of four leeters are possible as call letter? what is the probility of having call letters KIDS? Click here to see answer by stanbon(57307)

 Question 276489: Please help me solve this problem A Family composed of a father a mother and 3 kids are to be arranged in a row to have their picture taken. a) In how many ways can this be done? b) In how many ways can this be done if the father is to be on one end of the picture and the mother on the other? Click here to see answer by stanbon(57307)

 Question 276476: a NEW CAR SALESMEN KNOWS THAT HE SELLS CARS TO ONE CUSTOMER OUT OF TEN WHO ENTERS THE SHOW ROOM.WHAT IS THE PROBABILITY THAT HE WILL SELL A CAR TO EXACTLY 2 OF THE NEXT 3 CUSTOMERS.IS IT: 1)0.027 2)0.973 3)0.000 4)0.090 5)0.901 Click here to see answer by stanbon(57307)

 Question 276766: Of Every 4000bolts produced in a factory, 800 of them are faulty what is the probability of a bolt chosen at random NOT being faulty ? Click here to see answer by checkley77(12569)

 Question 276765: At a lumber company, shelves are sold in 3 types of wood, 3 different widths and 5 different lengths. How many different types of shelves could be ordered? Click here to see answer by checkley77(12569)

 Question 276759: License plates are made using 2 letters followed by 2 digits. How many plates can be made if repetition of leters and digits is allowed? Click here to see answer by checkley77(12569)

 Question 276801: A carnival gave offers a \$100 cash prize for anyone who can break a balloon by throwing a dart at it. It costs \$5 to play, and you're willing to spend up to \$20 trying to win. You estimate that you have about 10% chance of hitting the balloon on any throw. 1. Create a probability model for this carnival game. 2. Find the expected number of darts you'll throw. 3. Find your expected winnings. Click here to see answer by stanbon(57307)

 Question 276904: An auto parts manufacturer finds that the useful life of a spark plug in a car is approximately normally distrbuted with a mean of 9 months and a standard deviation of 2.5 months. What is the probability that a randomly selected plug will last more than 7 months. Click here to see answer by stanbon(57307)

 Question 277086: A spinner has ten equal-size sections numbered from 1 to 10. Find the probability of each event when you spin the spinner. 6. P(even or multiple of 5) 7. P(multiple of 3 or multiple of 4) Click here to see answer by checkley77(12569)

 Question 277121: I'm having difficulty with these problems if anyone could help I'd really appreciate it. The first one: A exam has 5 questions with 4 choices each and one correct answer per question 1. How many ways can you fill out a answer sheet 2. How many ways can you fill out the sheet to have 4 answers correct and 1 incorrect 3. If a student guesses randomly at each, what is the probability the student gets three or fewer correct The second question: Possible grades include A, B, C, D, and F. 1. Seven students in a class, how many ways can a teacher assign grades to the class 2. How many ways can a teacher assign grades to seven students if nobody gets an F but only one student gets an A Click here to see answer by stanbon(57307)

 Question 277208: A student scored 69 percent on a test, and was in teh 44th percentile. Explain these two numbers. Click here to see answer by JBarnum(2044)

 Question 277185: 1.A board game uses tokens with colored plastic and each token has 4 different regions with a different color: either red, green, yellow, blue, orange, or purple. How many different tokens are possible? 2. Identification codes are given sequentially, starting with 0000, 0001, 0002, 0003, 0004, etc. When this reaches 9999, a new form from the set (A...Z) begins in order is added. After this, the sequence of identifaction adds two letters, so the process is as follows: 0000 ... 9999, A0000, A0001, ..., A9999, B0000, B0001 ...., B9999 ... Z0000, Z0001, Z9999, AA0000, AA0001, .... Using this info., describe the number identification codes you can have using two or fewer letters. Click here to see answer by stanbon(57307)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400, 5401..5445, 5446..5490, 5491..5535, 5536..5580, 5581..5625, 5626..5670, 5671..5715, 5716..5760, 5761..5805, 5806..5850, 5851..5895, 5896..5940, 5941..5985, 5986..6030, 6031..6075, 6076..6120, 6121..6165, 6166..6210, 6211..6255, 6256..6300, 6301..6345, 6346..6390, 6391..6435, 6436..6480, 6481..6525, 6526..6570, 6571..6615, 6616..6660, 6661..6705, 6706..6750, 6751..6795, 6796..6840, 6841..6885, 6886..6930, 6931..6975, 6976..7020, 7021..7065, 7066..7110, 7111..7155, 7156..7200, 7201..7245, 7246..7290, 7291..7335, 7336..7380, 7381..7425, 7426..7470, 7471..7515, 7516..7560, 7561..7605, 7606..7650, 7651..7695, 7696..7740, 7741..7785, 7786..7830, 7831..7875, 7876..7920, 7921..7965, 7966..8010, 8011..8055, 8056..8100, 8101..8145, 8146..8190, 8191..8235, 8236..8280, 8281..8325, 8326..8370, 8371..8415, 8416..8460, 8461..8505, 8506..8550, 8551..8595, 8596..8640, 8641..8685, 8686..8730, 8731..8775, 8776..8820, 8821..8865, 8866..8910, 8911..8955, 8956..9000, 9001..9045, 9046..9090, 9091..9135, 9136..9180, 9181..9225, 9226..9270, 9271..9315, 9316..9360, 9361..9405, 9406..9450, 9451..9495, 9496..9540, 9541..9585, 9586..9630, 9631..9675, 9676..9720, 9721..9765, 9766..9810, 9811..9855, 9856..9900, 9901..9945, 9946..9990, 9991..10035, 10036..10080, 10081..10125, 10126..10170, 10171..10215, 10216..10260, 10261..10305, 10306..10350, 10351..10395, 10396..10440, 10441..10485, 10486..10530, 10531..10575, 10576..10620, 10621..10665, 10666..10710, 10711..10755, 10756..10800, 10801..10845, 10846..10890, 10891..10935, 10936..10980, 10981..11025, 11026..11070, 11071..11115, 11116..11160, 11161..11205, 11206..11250, 11251..11295, 11296..11340, 11341..11385, 11386..11430, 11431..11475, 11476..11520, 11521..11565, 11566..11610, 11611..11655, 11656..11700, 11701..11745, 11746..11790, 11791..11835, 11836..11880, 11881..11925, 11926..11970, 11971..12015, 12016..12060, 12061..12105, 12106..12150, 12151..12195, 12196..12240, 12241..12285, 12286..12330, 12331..12375, 12376..12420, 12421..12465, 12466..12510, 12511..12555, 12556..12600, 12601..12645, 12646..12690, 12691..12735, 12736..12780, 12781..12825, 12826..12870, 12871..12915, 12916..12960, 12961..13005, 13006..13050, 13051..13095, 13096..13140, 13141..13185, 13186..13230, 13231..13275, 13276..13320, 13321..13365, 13366..13410, 13411..13455, 13456..13500, 13501..13545, 13546..13590, 13591..13635, 13636..13680, 13681..13725, 13726..13770, 13771..13815, 13816..13860, 13861..13905, 13906..13950, 13951..13995, 13996..14040, 14041..14085, 14086..14130, 14131..14175, 14176..14220, 14221..14265, 14266..14310, 14311..14355, 14356..14400, 14401..14445, 14446..14490, 14491..14535, 14536..14580, 14581..14625, 14626..14670, 14671..14715, 14716..14760, 14761..14805, 14806..14850, 14851..14895, 14896..14940, 14941..14985, 14986..15030, 15031..15075, 15076..15120, 15121..15165, 15166..15210, 15211..15255, 15256..15300, 15301..15345, 15346..15390, 15391..15435, 15436..15480, 15481..15525, 15526..15570, 15571..15615, 15616..15660, 15661..15705, 15706..15750, 15751..15795, 15796..15840, 15841..15885, 15886..15930, 15931..15975, 15976..16020, 16021..16065, 16066..16110, 16111..16155, 16156..16200, 16201..16245, 16246..16290, 16291..16335, 16336..16380, 16381..16425, 16426..16470, 16471..16515, 16516..16560, 16561..16605, 16606..16650, 16651..16695, 16696..16740, 16741..16785, 16786..16830, 16831..16875, 16876..16920, 16921..16965, 16966..17010, 17011..17055, 17056..17100, 17101..17145, 17146..17190, 17191..17235, 17236..17280, 17281..17325, 17326..17370, 17371..17415, 17416..17460, 17461..17505, 17506..17550, 17551..17595, 17596..17640, 17641..17685, 17686..17730, 17731..17775, 17776..17820, 17821..17865, 17866..17910, 17911..17955, 17956..18000, 18001..18045, 18046..18090, 18091..18135, 18136..18180, 18181..18225, 18226..18270, 18271..18315, 18316..18360, 18361..18405, 18406..18450, 18451..18495, 18496..18540, 18541..18585, 18586..18630, 18631..18675, 18676..18720, 18721..18765, 18766..18810, 18811..18855, 18856..18900, 18901..18945, 18946..18990, 18991..19035, 19036..19080, 19081..19125, 19126..19170, 19171..19215, 19216..19260, 19261..19305, 19306..19350, 19351..19395, 19396..19440, 19441..19485, 19486..19530, 19531..19575, 19576..19620, 19621..19665, 19666..19710, 19711..19755, 19756..19800, 19801..19845, 19846..19890, 19891..19935, 19936..19980, 19981..20025, 20026..20070, 20071..20115, 20116..20160, 20161..20205, 20206..20250, 20251..20295, 20296..20340, 20341..20385, 20386..20430, 20431..20475, 20476..20520, 20521..20565, 20566..20610, 20611..20655, 20656..20700, 20701..20745, 20746..20790, 20791..20835, 20836..20880, 20881..20925, 20926..20970, 20971..21015, 21016..21060, 21061..21105, 21106..21150, 21151..21195, 21196..21240