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

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

Question 640624: In how many ways can 7 people seated on a sofa if there are only 4 seats available?

Click here to see answer by reviewermath(534)

Question 640844: Assume that the pointer can never lie on a border line. Find the following probabilities. (Enter each answer as a fraction.)
P(A) =
P(B) =
P(C) =
P(D) =
P(E) =
P(F) =
P(G) =
P(H) =
P(I) =
Click here to see answer by solver91311(16897)

Question 640871: I have 3 red socks, 4 blue socks and 6 green socks in a drawer. What is the probability that I will NOT pick a blue sock?
Click here to see answer by jim_thompson5910(28598)

Question 640866: There are 20 pennies, 15 nickels, 3 dimes, and 12 quarters.
what are the odds of picking a value less than $0.25?

Click here to see answer by solver91311(16897)

Question 638817: In many cases probability is associated with risk where we need to know the Expected Value to assess the fairness of the risk. Provide one example to show how you can use the Expected Value computation to assess the fairness of a situation (probability experiment). Provide the detailed steps and calculations.
Click here to see answer by lovelylady65(2)

Question 641075: The board of directors of a small company consists of five people. Three of those are " strong leaders." if they buy idea, the entire board will agree. The other " weak" members have no influence. Three salesmen are scheduled, one after the other, to make sales presentations to a board member of the salesman's choice. the salesmen are convincing but do not know who the "strong leaders" are. However, they will know who the previous salesmen spoke to. the first salesman to find a strong leader will win the account. Do the three salesmen have the same chance of winning the account? if not, find their respective probabilities of winning.
Click here to see answer by BloodMagic(2)

Question 641101: A coin that is balanced should come up heads half the time in the long run. The population for coin tossing contains the results of tossing the coin forever. The parameter p os the probability of a head, which is the proportion of all tosses that give a head. A coin is tossed 4040 times and gives 2085 heads. Is the coin biased? Use alpha =.05
Click here to see answer by reviewermath(534)

Question 641182: bill's scores on his first four science tests are 86,,90,84,and 91.what test score must bill earn on the fifth test so that his average (mean) will be exactly 88?
Click here to see answer by josh_jordan(115)

Question 641327: Suppose you have an extremely unfair coin: The probability of a head is ¼ and the probability of a tail is ¾. If you toss the coin 32 times, how many heads do you expect to see?
Click here to see answer by stanbon(57395)

Question 641370: "If the random variable z is the standard normal score and a > 0, is it true that P9z > -a) = P9z < a)"

Click here to see answer by stanbon(57395)

Question 641371: A multiple-choice test consist of 7 questions with each question having 5 possible answers, how many different ways are there to mark the answers?
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Question 641475: Over time, you have many conversations with a friend about your favorite actress, favorite musician, favorite book, favorite TV show, and so forth for 100 separate topics. On any given topic, there’s only a .02 probability that you agree. If you did agree on a topic, you would consider it to be coincidental.
a. If whether you agree on any two different topics are independent events, find the probability that you and your friend never have a coincidence on these 100 topics.
b. Find the probability that you have a coincidence on at least one topic.

Click here to see answer by stanbon(57395)

Question 641530: If the mean of a normal distribution is 70 and the standard deviation is 10 what is the probability the item selected at random for this sample will be greater than 80?
Click here to see answer by stanbon(57395)

Question 641493: Suppose we test the difference between two proportions at the 0.05 level of significance. If the computed z is -1.07, what is our decision?
A. Reject the null hypothesis.
B. Do not reject the null hypothesis.
C. Take a larger sample.
D. Reserve judgment.

Click here to see answer by stanbon(57395)

Question 641738: Assuming that each child has the probability 0.5 being a boy. Find the probability that a family of 4 children has:
a. exactly one boy
b. 2 or 3 boys
c. all girls and
d. at least one boy
Click here to see answer by DrBeeee(378)

Question 641875: Determine whether each of the distributions given below represents a probability distribution. Justify your answer.

(A)
x
1
2
3
4

P(x)
3/10
1/5
1/5
3/10

(B)
x
3
6
8

P(x)
0.2
3/5
3/10

(C)
x
20
30
40
50

P(x)
1/10
0.1
1/2
0.3

Click here to see answer by solver91311(16897)

Question 642181: a bag contains 2 white, 5 red, and 3 blue marbles. What is the highest number of pieces you can draw from the without drawing a white piece?
Click here to see answer by katbit(6)

Question 642021: lily has a bag of marbles with 8 red marbles 12 blue marbles and ten green marbles, if her friend patty takes one marble out of the bag at random which number choice is the probability that the marble is green
Click here to see answer by katbit(6)

Question 642229: 3 white chips, 7 blue chips, 16 green chips, 2 chips drawn from the box in succession what is the probability that one is blue and other is white?

Click here to see answer by stanbon(57395)

Question 642259: There are 9 balls put inside a bag. The balls are either white or black! How many balls will be white? And how many balls will be black? Use algebra
Click here to see answer by Edwin McCravy(8912)

Question 642356: What are the chances of being dealt a hand that will lose to a flush?
Click here to see answer by Edwin McCravy(8912)

Question 642403: an accountant can pick 3 out of 50 tax returns to get a special audit. how many ways can these 3 be picked if the order does matter?
Click here to see answer by stanbon(57395)

Question 642468: 1) a battery is found to have a mean life of 219 hours with a standard deviation of 70 hours. what is the probability that the battery will not last 100 hours??
2) students in the grade have an average height of 66 inches with a standard deviation of 3 inches. whats the probability that a student is less then 68 inches tall??
3) a bolt manufacturer makes bolts that have a mean diameter of of 1 cm with a standard deviation of 0.05. whats the probability that the diameter of the bolt will exceed 1.03 cm??
4) of popcorn kernels that pop successfully, the mean popping time for one batch is 4 min with a standard deviation of 1 min. what is the probability that a specific kernel will pop after 5 1/2 min
As you can see it is allot and its due tommorow morning so please help me solve these problems ASAP
Click here to see answer by stanbon(57395)

Question 642863: if your expected value when playing a $1 game of chance is $0.08. How much should you have netted after playing the game 140 times?

Click here to see answer by MathLover1(6638)

Question 642871: please help me solve this equation:x + 9>14
Click here to see answer by stanbon(57395)

Question 642865: Hi. I'm having trouble with a statistics question. I want to verify that the answer I got is correct.
Question: A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. Using = .05, what is the value the test statistic?
Women Men
Sample size 50 /80
Mean effect 7 /6.95
Sample standard deviation 3 /4
Possible Answers:A. t = 3.252 B. z = 0.455 C. z = 0.081 D. z = 0.151
I got C as my answer. Is this correct?

Click here to see answer by stanbon(57395)

Question 642875: A book contains pages numbered from 1 to 48. A page is chosen at random. What is the probability that its page number contains a 3?
Click here to see answer by Edwin McCravy(8912)

Question 642849: OF THE STUDENTS AT A COMMUNITY COLLEGE,41%SMOKE CIGARATES.SIX STUDENTS ARE RANDOMLY SELECTED TO BE INTERVIEWD FOR THIER VIEWS ON SMOKING.THE -PROBABILITY THAT AT LEAST HALF OF THESE SIX STUDENTS SMOKE IS GIVEN BY?
Click here to see answer by stanbon(57395)

Question 642864: Hi! I have a word problem here that asks three questions. I have managed to answer the 1st and 3rd questions, but I am having trouble with the 2nd and I would like some help. Also, if you could ensure my answers that I have are correct, I would appreciate it! Thank you!
The marketing manager of a large supermarket chain would like to use shelf space to predict the sales of pet food. For a random sample of 12 similar stores, she gathered the following information regarding the shelf space, in feet, devoted to pet food and the weekly sales in hundreds of dollars. Use these data to answer questions 1 through 3.

Store 1 2 3 4 5 6
Shelf Space 5 5 15 20 20 20
Weekly Sales 1.6 2.2 1.4 1.9 2.4 2.6

Store 7 8 9 10 11 12
Shelf Space 25 25 25 30 30 30
Weekly Sales 2.3 2.7 2.8 2.6 2.9 3.1
Question 1: Compute the value of the sample correlation coefficient between weekly sales and shelf space. Possible answers A. 0.6234 B. 0.827 C. 0.652 D. 0.741 I answered D
Question 2: Is the correlation between weekly sales and shelf space significant at the .01 level of significance? Possible answers: A. No, the sample correlation coefficient does not exceed the critical value. B. Yes, the p-value of the test for significance is not than .01. C. Yes, the value of the test statistic does exceed the critical value. D. Yes, the computed t-test statistic is less than the critical value.
Question 3: What is the estimated regression equation? A. = 1.45 + 0.044x B. = 1.45 + 0.724x C. = 1.45 - 0.074x D. = 2.63 - 0.174x I answered A.

Click here to see answer by stanbon(57395)

Question 643088: One card is selected from a deck of playing cards. Determine the probability of selecting a card greater than nine or a black card. Show your work
Click here to see answer by stanbon(57395)

Question 643270: "A researcher found that 85% of customers who make purchase at a department store are please with the store customer service. We asked 20 customers whether or not they are pleased with the store customer service. Is this a binomial experiement? Use the correct formula to find that the probability that, out of 20 customers, exactly 12 of them are pleased with the customer service."
Click here to see answer by stanbon(57395)

Question 642970: A student has to sit for an examination consisting of 3 questions selected randomly from a list of 100 questions. To pass, he should answer all the three questions. What is the probability that the student will pass the examination, if he knows the answer to 90 questions on the list.
Click here to see answer by stanbon(57395)

Question 643440: please help in solving this question :
Martin beats Jelena in 2 games out of 3 at tennis . what is the probability that jelena wins a set of tennis 6 games to 4 ?

tushar.langer@gmail.com
Click here to see answer by Edwin McCravy(8912)

Question 643396: THE PROBABILITY THAT AN AMERICAN INDUSTRY WILL LOCATE IN MUNICH IS 0.7, THE PROBABILITY THAT IT WILL LOCATE IN BRUSSELS IS 0.4, AND THE PROBABILITY THAT IT WILL LOCATE IN EITHER MUNICH OR BRUSSELS OR BOTH IS 0.8. WHAT IS THE PROBABILITY THAT THE INDUSTRY WILL LOCATE
A. IN BOTH CITIES?
B. IN NEITHER CITY?
Click here to see answer by Theo(3464)

Question 643651: This question really has me stumped.
A banker knows from previous experience that 3% of loans will default. He makes 50 loans in a day. What is the probability that 5 of those 50 loans will default?
I tried viewing it as each loan either defaults or it doesn't so each loan is a .5% probability.
Which gave me 0.5 x 0.5 x 0.5 x 0.5 x 0.5 = 0.03125 but that seems to completely negate the need for the previous experience factor given.
Click here to see answer by solver91311(16897)

Question 643705: what are the odds in favor of drawing a spade from an ordinary deck of cards?

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Question 643777: A single card is drawn from a standard deck of cards. Find the following probabilities. A face card is a jack, queen, or king.
P(jack/red)=
Click here to see answer by stanbon(57395)

Question 643561: a sociologist is interested in drawing a random sample of six individuals from a group consisting of ten males and ten females. how many different samples of size six are possible?
Click here to see answer by stanbon(57395)

Question 643972: Bank robbers brandish firearms to threaten their victims in 80% of the incidents. An announcement that six bank robbers are taking place is being broadcast. What is the probability that a firearm is being used in atleast one of the robberies?
Click here to see answer by stanbon(57395)

Question 643964: Here is another Id like help with
A new car salesperson knows that he sells the car to one customer out of 10 who enters the showroom. What is the probability that he will sell thhe car to exactly 2 of the next 3 customers
Click here to see answer by stanbon(57395)

Question 643962: Please help me with this question...
Pravesh and Solly usually go to a coffee shop during luch break and toss a coin to see who will pay. what is the probability that Pravesh will pay 3 days in a row?
Click here to see answer by stanbon(57395)

Question 643927: 1. a committee of 5 is to be selected from 10 seniors and 15 juniors. what is the probability that the committee is to consist of at most juniors?
2. a number of 2 different digits is to be formed from the digits 1, 2 ,3, 4, and 5. determine the probability of each of the following events:
a. the no. is odd
b. no is greater than 25
Click here to see answer by stanbon(57395)

Question 644043: Find the (two) z-scores that bound the middle 40% of the standard normal distribution.
Click here to see answer by stanbon(57395)

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, 21241..21285