Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 101958: An extra credit problem Im struggling with.
Of 200 students who took Mr Johns Algebra class, 160 passed the mid-term exam and 140 passed the the final exam. 124 students passed both exams. Let A represent the students who passed the mid-term, and B represent those who passed the final. There were no other graded requirements. Use probability notation to describe and solve the following.
a. What is the probability that a student chosen at random passed the mid-term?
I have 1/200 or should it be 160/200?
b. What is the probability a student chosen at random passed the final? Again I have 1/200 or should it be 160/200
c.What is the probability a student chosen at random passed both exams?
I have once again 1/200 or should it be 124/200?
d. What is the probability of receiving a passing grade in Mr Johns Algebra class IF a student can pass JUST ONE test and STILL PASS the class?
Im confused and need help. The last question is making my head spin.
Then to put each one in probability notation. Oh Boy!!
Click here to see answer by stanbon(57314)  |
Question 102628: A roulette wheel in the U.S. has 18 red slots, 18 black slots and 2 green slots. You can bet $1 on either red or black. I fyou win, you get your $1 back plus an additional $1. If you lose, you lose your $1 bet. What are your expected winnings on one spin of the wheel (include the variance and standard deviation for all)? Two successive 1$ bets on the wheel? A single $2 bet? 100 successive $1 bets?
Click here to see answer by stanbon(57314) |
Question 102626: Here is my probability question...In a dice game, you will roll three dice: a red one, a green one, and a blue one. You will win , in dollars, 3 times the number on the red die, plus 2 times the number on the green die, minus the number on the blue die. What are the expected value and standard deviation of your winnings? What would be a fair price to pay to play this game?
Click here to see answer by stanbon(57314) |
Question 102623: Here is my difficult question using probability statistics. Suppose weights in pounds of workers at a large office building can be modeled by a N(165,30) distribution. The elevator capacity is 1800 pounds. What's the probability that the total weight of 10 randomly selected workers would exceed this capacity?
Click here to see answer by stanbon(57314) |
Question 102622: Here is my problem that I am working through on probabilities of random variables. Suppose heights of men in inches follow a N(71,3) model and heights of women follow a N(67, 2.5) model. If I randomly choose a man and randomly choose a woman, what's the probability that the woman will be taller than the man?
Click here to see answer by stanbon(57314) |
Question 102763: 8 3 9 x 8 5
When a number is chosen at random from the six numbers listed above, the probability that this number will be less than 7 is 1/2. Which of the following could be the value of x?
a) 6
b) 7
c) 8
d) 9
e) 10
Click here to see answer by Nate(3500) |
Question 103004: A group consists of 5 males and 6 females. Four people are selected from the group.
1. In how many ways can we choose 4 people from those 11?
2. In how many ways can we choose 4 females from the 6 females?
3. What is the probability that we get all 4 females when we choose 4 from the whole group?
4. What is the probability that we get at least 1 male when we choose 4 from the whole group?
Click here to see answer by stanbon(57314) |
Question 102975: What is the P-value for the testing of the following hypothesis for someone who gets 25 right out of 100? 30 right? 35 Right? 50 right?
The null hypothesis is p=.2 that a person is guessing in an ESP experiment where one person randomly draws one of 5 cards and the "reciever" person tries to determine which card it is. The alternative hypothesis is p>.2 is to show support that the person is doing better than guessing.
Click here to see answer by stanbon(57314) |
Question 103678: A license plate has 6 positions for letters and numbers. The first two positions must be letters. The last four positions must be nonzero whole numbers. How many different license plates can be produced using this combination of letters and numbers?
Click here to see answer by stanbon(57314) |
Question 103678: A license plate has 6 positions for letters and numbers. The first two positions must be letters. The last four positions must be nonzero whole numbers. How many different license plates can be produced using this combination of letters and numbers?
Click here to see answer by Fombitz(13828)  |
Question 103841: Here is the titanic data we are working with...
died survived total
female 126 344 470
male 1364 366 1730
total 1490 710 2200
We are asked to show why the general addition rule is true and the hint was to use Venn Diagrams.
I have done P(A or B) = p(A) + p(B) - P (A and B)
.21+.73-.32=.62 but I don't understand "how to show that the General Addition Rule is True"?
Thanks for explaning this to me.
Jessica
Click here to see answer by stanbon(57314) |
Question 103841: Here is the titanic data we are working with...
died survived total
female 126 344 470
male 1364 366 1730
total 1490 710 2200
We are asked to show why the general addition rule is true and the hint was to use Venn Diagrams.
I have done P(A or B) = p(A) + p(B) - P (A and B)
.21+.73-.32=.62 but I don't understand "how to show that the General Addition Rule is True"?
Thanks for explaning this to me.
Jessica
Click here to see answer by Edwin McCravy(8908)  |
Question 104130: I need help filling in the numbers in an equation that is used for finding binomial probabilty:
P(k successes)= 
This is for a project that I am doing and it includes tossing one coin 100 times and then separating the 100 results into groups of 5 (20 groups/trials total). My teacher said that the numbers for the equation are as follows: n=5 because each trial has 5 tosses, k=6 because heads can show up 6 different ways in a trial ( not at all, once, 2 times, 3 times, 4 times, and 5 times), and
p(not P)=.5 because it's a fifty/fifty chance of one toss being heads or tails. I filled these into the equation and it always equals 0. Can you help me find the right numbers to fill in this equation and where they should go into it? By the way, the k after (p) should be an exponent [not the (1-p)], and the n-k should be an exponent.
Click here to see answer by stanbon(57314) |
Question 104171: Reggie Miller of the Indiana Pacers is the National Basketball Association's best career free throw shooter, making 89% of his shots (USA Today, January 22, 2004). Assume that late in a basketball game, Reggie Miller is fouled and is awarded two shots.
a. What is the Probability that he will make both shots?
b. What is the probability he will make at least one shot?
c. What is the probability he will miss both shots?
Click here to see answer by stanbon(57314) |
Question 104173: Probability-and-statistics: Last fall, a sample of n = 25 freshmen was selected to participate in a new 4-hour training program designed to improve study skills. To evaluate the effectiveness of the new program, the sample was compared with the rest of the freshman class. All freshman must take the same English Language skills course, and the mean score on the final exam for the entire freshman class was μ = 74. The students in the new program had a mean score of M = 78 with SS = 2400.
a. on the basis of these data, can the college conclude that the students in the new program performed significantly better than the rest of the freshman class? Use a one-tailed test with α = .05
b. Can the college conclude that the students in the new program are significantly different from the rest of the freshman class? Use a two-tailed test with α = .05.
Click here to see answer by stanbon(57314) |
Question 104110: Numerous studies have shown that IQ scores have been increasing, generation by generation, for years (Flynn, 1984, 1999). The increase is called the Flynn Effect, and the data indicate that the increase appears to be about 7 points per decade. To demonstrate this phenomenon, a researcher obtains an IQ test that was written in 1980. At the time the test was prepared it was standardized to produce a population mean of μ = 100. The researcher administers the test to a random sample of n =16 of today’s high school students and obtains a sample mean IQ of M = 121 with SS = 6000. Is this result sufficient to conclude that today’s sample scored significantly higher tan would be expected from a population with μ = 100. Use a one tailed test with α = 0.1
Click here to see answer by stanbon(57314) |
Question 104477: Find the probability that 2 friends never agree on two seperate topics out of 100. The probability that they agree on any given topic is 0.02, and ifthey did agree they would consider it a coincidence, and any two topics are independent events.
Click here to see answer by stanbon(57314) |
Question 105752: 9. A box contains four defective and six good electronic sensors. If five sensors are drawn, with replacement,
find the probability of drawing
(a) at most one defective
(b) at least one defective
(c) fewer than three defective
Click here to see answer by stanbon(57314) |
Question 105612: I am helping my son 12, with Marking period project.
Child playing a game with 3 frisbee's. There are four possible outcomes: A basket worth 1 point, a basket worth 5 points, a basket worth 10 points, and a miss of all baskets worth zero points.
What are the total possible point combinations for one turn of three frisbee's tossed ?
Click here to see answer by Fombitz(13828) |
Question 106287: Very important home work, please help:
The following data are from a research study comparing two treatment conditions. Do the data indicate a significant difference between treatments? Use a two tailed test with α = .05
a. For the first test, assume the data are from an independent-measures study using two separate samples.
Treatment 1 data= 10,2,1,15,7 with SS= 134 and M = 7
Treatment 2 data=11,5,2,18,9 with SS=150 and M =9
Click here to see answer by stanbon(57314) |
Question 106532: I have two questions if its ok:
1.) The formula for the volume of a rectangular box is V = lwh. If the length of a box is 22 inches, the height is 7 inches, and the total volume is 2,310 square inches, find the width of the box.
2.) A bus traveled on a level road for 3 hours at an average speed 20 miles per hour faster than it traveled on a winding road. The time spent on the winding road was 4 hours. Find the average speed on the level road if the entire trip was 305 miles.
Thank you!
Click here to see answer by Nate(3500) |
Question 106531: I have two problems if its ok:
1.) The equation 6x + 2 – 2x = 4x + 1 has no solution. Try solving this equation for x and see what happens. Explain why you cannot find a solution.
2.) An 18-foot wire is to be cut so that the longer piece is 5 times longer than the shorter piece. Find the length of each piece.
Thank you!
Click here to see answer by Nate(3500) |
Question 107021: How many points would you earn on an average per turn in a card game, played several time, where the face cards (kings, queens, and jacks) are each worth 20 points, 9's and 10's are worth 10 points each, Aces are worth 25 points each, and all other cards are worth zero points?
Click here to see answer by Annabelle1(69) |
Question 106873: There are 4 red, 4 white, 4 blue and 4 yellow balls in a bag (a total of 16 balls). They are picked at random. How many times you have to pick the balls (one at a time) so that you have at least one ball of each color in your hand?
Thank you.
Click here to see answer by stanbon(57314) |
Question 106761: A recent report stated that when eating a sandwich, 32% of U.S. adults cut it in half before eating it. If 9 U.S. adults are selected at random, what is the probability that exactly 4 cut their sandwich in half before eating it?
Click here to see answer by stanbon(57314) |
Question 107236: The mailing list of an agency that markets scuba-diving trips to the Florida Keys contains 75% males and 25% females. The agency calls 25 people chosen at random from its list.
(a) What is the probability that 17 of the 25 people are men?
wrong check mark
(b) What is the probability that the first woman is reached on the 8th call?
Click here to see answer by stanbon(57314) |
Question 107280: Two Russian mathematicians meet on a plane.
“If I remember correctly, you have three sons,” says Ivan. “What are their ages today?”
“The product of their ages is thirty-six,” says Igor, “and the sum of their ages is exactly today’s date.”
“I’m sorry, Igor,” Ivan says after a minute, “but that doesn’t tell me the ages of your boys.”
“Oh, I forgot to tell you, my youngest son has red hair.”
“Ah, now it’s clear,” Ivan says. “I now know exactly how old your three sons are.”
How did Ivan figure out the ages?
Click here to see answer by ankor@dixie-net.com(15649)  |
Question 107713: i need help with these probablity questions ans show me how you go to the answers
Three coins are flipped. Find the following probabilities:
a) P(two heads) =
b) P(at most two heads) =
c) P(no heads) =
A single die is rolled. Find the probabilities:
a) P(odd number greater than 1) =
b) P(number less than 5) =
c) P(the number 3 or 7) =
In the game of craps, a player rolls two balanced dice. There are 36 equally likely outcomes. What is the probability that
a) The sum is either 3 or 8?
b) The sum is 6 or "doubles" rolled?
c) The sum is 6 and "doubles" rolled?
d) The sum is 6 and both numbers are odd?
Consider a state lottery that has a weekly television show. On this show, a contestant receives the opportunity to win $1 million. The contestant picks from four hidden windows. Behind each is one of the following: $150,000, $200,000, $1 million, or a "stopper". Before beginning, the contestant is offered $100,000 to stop. Mathematically speaking, should the contestant take the $100,000? Justify your answer.
Click here to see answer by stanbon(57314) |
Question 108363: Thirteen percent of people are left handed. You randomly select 8 persons and ask them if they are left-handed. Find the probability that (a) exactly 1 person are left handed (b) at least 1 persons are left handed, and (C) less than 1 are left handed.
Click here to see answer by stanbon(57314) |
Question 108365: Suppose that twenty-eight percent of women consider themselves hockey fans. You randomly select 9 of the population and ask each if they are hockey fans. Construct a binomial distribution and use the distribution to find the mean, variance, and standard deviation of the binomial distribution.
Click here to see answer by stanbon(57314) |
|
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
|
