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

Tutors Answer Your Questions about Probability-and-statistics (FREE)

Question 347866:
Click here to see answer by Fombitz(13828)

Question 347754: There are 6 multiple-choice questions on an exam, each with four possible answers. Only one answer per question counts as the correct answer. If you guess on each question, what is the probability that you correctly answer all six questions?
Click here to see answer by stanbon(57352)

Question 347933: In a large vase, there are 8 roses, 5 daisies, 12 lilies, and 9 orchids. If 4 flowers are selected at random, find the probability that at least 1 of the flowers is a rose.
Click here to see answer by stanbon(57352)

Question 347921: In a blood testing procedure, blood samples from 6 people are combined into one mixture. The mixture will only test negative if all the individual samples are negative. If the probability that an individual sample tests positive is 0.11, what is the probability that the mixture will test positive
Click here to see answer by stanbon(57352)

Question 347918: A "combination" lock has a three-number "combination" where the numbers are
chosen from the set {1, 2, 3, ... , 19, 20}.What is the probability that the "combination" has no repeated numbers?
A. .00015 B. .75 C. .15 D. .855
Click here to see answer by jim_thompson5910(28595)

Question 347964: A coin will be thrown until it lands head up or until the coin has been thrown
five times. Draw a probability tree to represent the experiment. I've done it but want to see if i did it right.
Click here to see answer by jim_thompson5910(28595)

Question 347955: number between 1-20 odds of getting an even number
Click here to see answer by jim_thompson5910(28595)

Question 348002: A group of three seniors, six juniors, and five sophomores must select a committee of three. How many committes are possible of the committtee must contain the following:
a. one person from each class
b. Any mixture of the classes.
c. Exactly two seniors.
Click here to see answer by jim_thompson5910(28595)

Question 347994: The Student number at a University consists of 2 letters, followed by 4 digits followed by 2 letters. How many different student numbers are possible if:
a. Letters and digits cannot be repeated.
b. Letters can be repeated, but digits cannot
Click here to see answer by checkley77(12569)

Question 347965: You have 5 keys on a key ring, 2 of the keys unlock the door. Find the
probability of opening the door on the first or second try. Draw a tree diagram
to illustrate.
Click here to see answer by Edwin McCravy(8909)

Question 348023: Hello! I'm just having some trouble with a question on an assignment I have due Monday.
Question: Charlie is 5 years old. He is a very picky eater and can count to 5. His dad makes him a giant bowl of grapes containing only good grapes with the same proportion of red, green, and black grapes. (0.22 Green grapes, 0.24 Black grapes, and 0.54 red grapes. I calculated this in the previous problem.) Charlie randomly picks out 5 grapes from the bowl with replacement after each grape. Charlie will eat one of the grapes that has the majority in 5. If there is a tie, Charlie will not eat a grape in that round. Charlie's dad replaces the grape that has been eaten after each round.
a) Let g be the event of Charlie eating a green grape. Determine the theoretical probability of event g, P(g)
Any help would be appreciated. Thank you so much! :)
Click here to see answer by scott8148(6628)

Question 348063: In a shipment of 78 vials, only 18 do not have airline cracks. If you randomly select 3 vials from the shipment, what is the probability that none of the 3 vials have airlines? what is the probability that all 3 selected have airlines?
Click here to see answer by stanbon(57352)

Question 348132: An office employs seven women and five men. One employee will be randomly selected
to receive a free lunch with the boss. What is the probability that the selected employee will be a woman?
Click here to see answer by stanbon(57352)

Question 348285: A sample of employees at a large chemical plant was asked to indicate a preference for one of three pension plans. The results are given in the following table. Does it seem that there is a relationship between the pension plan selected and the job classification of the employees? Use the .01 significance level.
Pension Plan
Job Class Plan A Plan B Plan C
supervisor 10 13 29
clerical 19 80 19
labor 81 57 22

Click here to see answer by stanbon(57352)

Question 348343: Urn A has 6 white and 4 red balls. Urn B has 16 white and 13 red balls. We flip a fair coin. If the oucome is heads, then a ball from urn A is selected, whereas if the oucome is tails, then a ball from urn B is selected. Suppose that a red ball is selected. What is the probability that the coin landed heads?
Please show your work. Thank you so much! :]
Click here to see answer by math10123(2)

Question 348451: The standard deviation of test scores on a certain achievement test is 10.5 . A random sample of scores on this test had a mean of 72.8. Based on this sample, find a 90% confidence interval for the true mean of all scores. Then complete the table below.
Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.
The lower limit of 90% confidence interval =
The upper limit of 90% confidence interval =

Click here to see answer by stanbon(57352)

Question 348457: 3. The results of a survey of 800 married couples and the number of children they had is shown below.
Number of Children Probability
0 0.050
1 0.125
2 0.600
3 0.150
4 0.050
5 0.025
If a couple is selected at random, what is the probability that the couple will have
a. Less than 4 children?
b. More than 2 children?
c. Either 2 or 3 children?

Click here to see answer by stanbon(57352)

Question 348461: It has been observed in one country that 56 out of every 100 births is a baby wiht brown eyes. In 670 births how many brown eyed babies would you expect?
Click here to see answer by lunaclock(3)

Question 348405: Please help with this problem.
On a standard measure of hearing ability, the mean is 300 and the standard deviation is 20. Give the Z score for persons who score (a) 340, (b) 310, and (c) 260. Give the raw scores for persons whose z scores are on this test are (d) 2.4, (e)1.5, (f) 0, and (g) -4.5
Please show work on how to get the z score and raw scores. Thank you
Click here to see answer by stanbon(57352)

Question 348353: What is the critical value for a two-tail, one sample hypothesis test in which a null hypothesis is tested at the 5% level of significance based on a sample size of 23?
A. 1.717
B. 1.714
C. 2.069
D. 2.074

Click here to see answer by stanbon(57352)

Question 348475: 50 Americans, 45 Europeans and 1 Asian are forming a committee and 3 representatives are to be chosen at random to head the committee. Using number of combinations, find probability that the group of three consists of one American, one European and 1 Asian.
Click here to see answer by edjones(7569)

Question 348560: Two fair dice are rolled 5 times. Let the random variable x represent the number of times that the sum 7 occurs. The table below describes the probability distribution. Find the value of the missing probability.
x P(x)
0 0.401877572016461
1
2 0.160751028806584
3 0.0321502057613169
4 0.00321502057613169
5 0.000128600823045267
Click here to see answer by Jk22(389)

Question 348529: . If a family has three children, find the probability that it has two girls, given that at least one child is a boy.
Click here to see answer by stanbon(57352)

Question 348612: I need help with this one: When selecting a card from a regular deck of 52 playing cards, what is the probability that the card is not a king AND not a spade.
I have tried to go about it while taking out all of the kings and all of the rest of the spades which adds up to 12 spades minus the king. I am having problems with the rest of the computation.
Click here to see answer by stanbon(57352)

Question 348633: A family has 5 children.
a. Find the probability that exactly 2 are male
b. What is the probability that exactly 2 are female if the first child born is male?
c. Find the probability that the last child born is male
Click here to see answer by Fombitz(13828)

Question 348668: Please Find the probability of getting the outcome of heads and 4 when a coin is tossed and a single die is rolled.
Enter the exact answer in a fraction form, like, for example, 2/7.
Click here to see answer by solver91311(16885)

Question 348497: Please show me how to calculate this...
Variables x & y have r=.52
If we decrease each x value by .1 and double each y value, the new correlation will be___________?

Thanks so much!!
Click here to see answer by QH(50)

Question 348707:
Number of trees 7 8 10 15
Trimming time per tree(minutes) 20 40 80 100

How many hours will it take to trim all 40 trees listed in the table above?

Click here to see answer by stanbon(57352)

Question 348740: Determine whether each of the following numbers is prime or composite
(a)219
(b)791
(c) 1001
Click here to see answer by Fombitz(13828)

Question 348742: Find each of the following
(a)GCD (12, 26, 65)
(b) LCM (12,26,65)
Click here to see answer by stanbon(57352)

Question 348722: Which symbol belongs between each pair of numbers?
<,>, or =
(a)11/23 and 33/65
(b)7/8 and 8/9
(c)-6/7 and -11/33
Hint (LCD)
Click here to see answer by checkley77(12569)

Question 348841: In order to determine an interval for the mean of a population with unknown standard deviation a sample of 61 items is selected. The mean of the sample is determined to be 23. The number of degrees of freedom for reading the t value is
a. 22
b. 23
c. 60
d. 61
Click here to see answer by stanbon(57352)

Question 348892: I am having a hard time in my Biostatistics class. I don't understand anything about it.Need someone to explain how to figure this out so i can complete the other questions.
Total cholesterol in children ages 10 to 15 years of age is assumed to follow a normal distribution with a mean of 191 and a standard deviation of 22.4.
a. What proportion of children 10 to 15 have a total cholesterol between 180 and 190?
b. What proportion of children 10 to 15 would be classified as hyperlipidemic(assume that hyperlipidemia is defined as a total cholesterol level over 200?
c. what is the 90th percentile of total cholesterol?
Click here to see answer by stanbon(57352)

Question 348916: An independent consumer testing lab preformed a statistical test on 25 type-C alkaline batteries and calculated the mean life for a particular use before they failed was 22.5 hours. The distribution of the lives approximated a normal distribution. The standard deviation of the distribution was 1.1 hours. Information on the package states that the batteries should last 24 hours.
The test question was if this difference between the test statistics and the stated life of the battery was significant? The .05 significant level was selected for the test. Which is the correct statement?

Click here to see answer by stanbon(57352)

Question 348920: ) An independent consumer testing lab preformed a statistical test on 25 type-C alkaline batteries and calculated the mean life for a particular use before they failed was 22.5 hours. The distribution of the lives approximated a normal distribution. The standard deviation of the distribution was 1.1 hours. Information on the package states that the batteries should last 24 hours.
The test question was if this difference between the test statistics and the stated life of the battery was significant? The .05 significant level was selected for the test. Which is the correct statement?
A. The difference was not significant.
B. The difference was significant; the batteries do not meet the stated length of time.
C. The difference indicates that the batteries are not good.
D. The difference cannot be evaluated with this small of a sample.

Click here to see answer by stanbon(57352)

Question 348956: When does P(A|B) = P(A)?

Click here to see answer by edjones(7569)

Question 348640: Of 12 applicants for an executive position, 7 were male and 5 were female. Find the probability that one picked is a female. What is the probability of picking a male?
Click here to see answer by nyc_function(2733)

Question 348638: Of 12 persons screened for Hepatitis B, 5 were female and 7 were male. Find the probability of selecting a female case at random.
Click here to see answer by nyc_function(2733)

Question 349004: In a bag of candies there are 13 red candies, 13 green candies, 13 yellow candies, and 13 blue candies. If you choose 1 candy from the bag, what is the probability the candy will not be blue?
Click here to see answer by edjones(7569)

Question 349023: A box of 6 coins (penny, nickel, dime or quarter) worth $0.67 is shaken. What is the probability that a nickel is drawn first and then a quarter? Assume no replacement and that all coins are equally likely.
The letters of the word Mississippi are placed in a hat. What is the probability that the first two letters drawn are both i if the first letter drawn is not replaced?
Click here to see answer by edjones(7569)

Question 349042: I have an issue with this problem for my probablity and statistics class. I hope you can help.
You are dealt two cards successively from a deck of 52 playing cards. Find the probability that both cards are black in a simplified fraction.
How is the problem figured out - the answer is 25/102
Please help : )
Click here to see answer by josmiceli(9680)

Question 349091: nathan will roll two 6-sided dice.what is the probability that he will roll a number less than three on the first die and a number greater than three on the second die? Express your answer as a common fraction.
Click here to see answer by Fombitz(13828)

Question 349095: An urn contains 4 red, 1 white, and 4 blue marbles. In how many ways can 3 red and 3 blue marble(s) be selected?

Click here to see answer by stanbon(57352)

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