Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 328757: An urn contains ten marbles, of which five are green, two are blue, and three are red. Three marbles are to be drawn from the urn, one at a time without replacement. What is the probability that all three marbles drawn will be green?
Click here to see answer by galactus(183)  |
Question 328623: The number of baby deliveries in a medium sized hospital was sampled over 12 hour periods. Below is the sample:
24 16 7 15 11 14 7 16 22 17
22 16 9 17 14 5 16 11 17 19
21
From this data set, compute the sample mean, median, mode and midrange. Compute the 1st
quartile and 3rd and interpret their meanings.
mean is the total of all units 316 / 21 = 15
median is 16
mode is 16 (appears 4 times)
midrange is (5 = 24)/2 = 14.5 or 15
Click here to see answer by Fombitz(13828)  |
Question 328774: Four equally qualified people apply for two identical positions in a company. One and only one applicant is a member of a minority group. The positions are filled by choosing two of the applicants at random.
a, list the possible outcomes for this experiment.
b, assign reasonable probabilities to the sample points.
c, find the probability that the applicant from the minority group is selected for a position.
Click here to see answer by Fombitz(13828)  |
Question 328782: An Airline in a small city has 5 departures each day. The local manager of the airline desire to make sure that the probability that all flights leave on time is 0.9. What is the largest probability of being late that the individual flights can have if the goal is to be achieved. Will the operation have to be improved significantly?
Click here to see answer by Fombitz(13828)  |
Question 328788: A rifleman can achieve a "marksman" award if he passes a test. He is allowed to fire six shots at a target's bull's eye.If he hits the bull;s eye with at least 5 of his 6 shots he wins a set. He becomes a marksman only if he can repeat the feat 3 times straight,that is,if he can wins three straight sets. If his probability is 0.8 of hitting a bull's eye on any one shot, find the probabilities of his: a) winning a set, and
b)becoming a marksman
Click here to see answer by stanbon(57203) |
Question 327963: A man wins a gambling game iif he gets two heads in five flips of a biased coin. The probability of getting a head with the coin is 0.7.
a)find the probability the man will win. Should he play this game?
b)What is the probability of winning if he wins by getting atleast 4 heads in five flips ? Should he play this new game?
Click here to see answer by Fombitz(13828)  |
Question 327560: Members of the general adult population volunteer an average of 4.2 hours per week. A random sample of 20 female college students and 18 male college students produced the results given in the table below. At the .01 level of significance, is there sufficient evidence to conclude that a difference exists between the mean number of volunteer hours per week for male and female college students?
Females Males
Sample size 20 18
Sample mean 3.8 2.5
Sample variance 3.5 2.2
Click here to see answer by stanbon(57203) |
Question 329004: There are 100 employees at Kiddie Carts International. Fifty-seven of the employees are
production workers, 40 are supervisors, 2 are secretaries, and the remaining employee
is the president. Suppose an employee is selected:
a. What is the probability the selected employee is a production worker?
b. What is the probability the selected employee is either a production worker or a supervisor?
c. Refer to part (b). Are these events mutually exclusive?
d. What is the probability the selected employee is neither a production worker nor a
supervisor?
Click here to see answer by stanbon(57203) |
Question 328985: Assuming that boy and girl babies are equally likely, fill in the remaining probabilities on the tree diagram and use the following information to find the probability that a family with three children has all girls, given the following.
42. The third is a girl
Click here to see answer by Fombitz(13828)  |
Question 329054: The time taken to install a new telephone is found to be normally distributed with a mean time equal to 60 minutes and a standard deviation of 12 minutes. The probability that the time to install a new telephone will be more than 36 minutes is
Click here to see answer by Fombitz(13828)  |
Question 328959: In previous section, we described an experiment in which the number 1,2,3,4, and 5 are written on slips of paper, and 2 slips are drawn at random one at a time without replacement. Find each probability in Excercises 16 and 17.
The probability that the first number is 3, given the following.
a. The sum is 7.
b. The sum is 8.
Click here to see answer by Fombitz(13828)  |
Question 329058: A random sample of 600 high school girls showed that during the previous month 42 took diet pills to lose weight. The researcher wants to test the hypothesis that less than 10% of high school girls take diet pills to lose weight. The test statistic is
Click here to see answer by stanbon(57203) |
Question 329136: (3) The data below shows the price of gas per litre and the price of rice per
bag in 2007 for eleven months.
GAS PER LITRE: 15.1 15.8 14.9 16.6 12.6 17.4 16.1 13.7 15.5 17.8 13.2
RICE PER BAG: 1692 1634 1835 1741 1876 1561 1921 1942 1822 1542 1874
Use the information to calculate correlation coefficient.
Click here to see answer by Fombitz(13828)  |
Question 329230: There are 100 employees at Kiddie Carts International. Fifty-seven of the employees are production workers, 40 are supervisors, 2 are secretaries, and the remaining employee is the president. Suppose an employee is selected:
a. What is the probability the selected employee is a production worker?
b. What is the probability the selected employee is either a production worker or a supervisor?
c. Refer to part (b). Are these events mutually exclusive?
d. What is the probability the selected employee is neither a production worker nor a
supervisor?
Click here to see answer by Fombitz(13828)  |
Question 327867: please i am still not understanding this can someone please help me out on how to work this problem.
The data below are the gestation periods, in months, of randomly selected animals and their corresponding life spans, in years.
Gestation, x 8 2.1 1.3 1 11.5 5.3 3.8 24.3
Life span, y 30 12 6 3 25 12 10 40
a. Find the equation of the regression line for the given data. Round the line values to the nearest two decimal places. (4 points) Show your work.
b. Using the equation found in part a, predict the life span when the gestation is 10 months. Round to the nearest absence.
Click here to see answer by Fombitz(13828)  |
Question 329231: A new chewing gum has been developed that is helpful to those who want to stop smoking. If 60 percent of those people chewing the gum are successful in stopping smoking, what is the probability that in a group of four smokers using the gum at least one quits smoking?
Click here to see answer by solver91311(16868)  |
Question 329255: A 20 question multiple-choice test has four possible answers for each question (A, B, C, or D). Suppose that you don't know the answers to any of the questions so you have to guess on each question. Then this situation follows a binomial distribution where X is the number of questions you get correct out of 20.
Find the probability that you get exactly 2 questions correct on the test.
Click here to see answer by stanbon(57203) |
Question 329387: Each soccer player gets 4 jerseys red, yellow, white and green. A player randomly draws 2 jerseys each from the bag. The first jersey is not placed back in the bag.
What is the probability of first drawing a white and then a green jersey?
What is the probability of drawing a red and yellow jersey in any order?
What is the probablity of not drawing a red jersey?
What is the probablity of having a white or red jersey after the second draw?
I would appreciate your help.
Thank you
Click here to see answer by Edwin McCravy(8879)  |
Question 329338: A presidential candidate's aide estimates that, among all college students, the proportion who intend to vote in the upcoming election is at most . If out of a random sample of college students expressed an intent to vote, can the aide's estimate be rejected at the level of significance?
Perform a one-tailed test.
Click here to see answer by stanbon(57203) |
Question 329413: An urn contains 8 brown marbles and 11 green marbles. Two marbles are drawn from the urn without replacement. What is the probability of drawing a green marble on the first draw and a brown marble on the second draw?
Click here to see answer by Fombitz(13828)  |
Question 329409: A Multiple-choice test has 15 questions with each having 4 possible answers with one correct. Assume a student randomly guesses the answer to every question.
a. What is the probability of getting exactly 5 correct answers?
b. What is the probability of getting less than 6 correct answers?
I have to have this in by TODAY - August 6th, 2010. Please help!
Click here to see answer by stanbon(57203) |
Question 329423: The probability that a cruise missile hits target on any particular mission is .80. Four cruise missiles are sent after the same target. What is the probability:
A. They all hit the target?
B. None hit the target?
C. At least one hits the target?
Click here to see answer by stanbon(57203) |
Question 329423: The probability that a cruise missile hits target on any particular mission is .80. Four cruise missiles are sent after the same target. What is the probability:
A. They all hit the target?
B. None hit the target?
C. At least one hits the target?
Click here to see answer by Fombitz(13828)  |
Question 329484: Of all the stores opened by a company, 90% survive. Assume that each store's chance of survival is independent of the others. What is the probability that at least 8 out of 10 stores opened will survive? please show all work, thanks
Click here to see answer by Fombitz(13828)  |
Question 329486: The probability is 1 in 4,000,000 that a single auto trip in the united states will result in a fatality. Over a liftime, an average u.s. driver takes 50,000 trips. What is the probability of a fatal accident over a lifetime?
1 / 4,000,000 = 0.00000025 0.00000025/50000 = 0.000000000005
Click here to see answer by stanbon(57203) |
Question 329555: For Questions 11 ~ 13
An airline company completed an on-board passenger survey of 400 customers in an attempt to measure the number of bags checked by those traveling on business or for pleasure. Results are shown in the table below:
Passenger 0 Checked 1 Checked 2 Checked 3 or more Total
Business
Pleasure 50
20 60
80 30
90 10
60 150
250
Total 70 140 120 70 400
11. What is the probability that a passenger who responded to the survey was a business customer? (Points 1)
a. 0.333 b. 0.375
c. 0.600 d. 1.000
12. What is the probability that a customer checked fewer than 2 bags? (Points 1)
a. 0.175. b. 0.525.
c. 0.825 d. 0.955
13. What is the probability that a customer was either traveling for pleasure or checked no bags? (Points 1)
a. 0.750 b. 0.625
c. 0.175 d. 0.800
Click here to see answer by stanbon(57203) |
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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, 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