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

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

Question 305318: A bag contains 10 red and 15 black balls.if 5 balls are drawn from bag what is probability we get at least one black ball?
Click here to see answer by stanbon(57347)

Question 305325: An urn contains 3 white and 5 black balls .one ball is drawn at random and its colour is unnoted laid aside.the another ball is drawn.what is probability that it is black or white???
Click here to see answer by vleith(2825)

Question 304903: Cass is taking a 5-question multiple-choice quiz in which each question has three choices. She guesses on all of the questions.
(a) What is the probability that Cass answers all of the questions correctly?
(b) What is the probability that he answers exactly three questions correctly?

Click here to see answer by ddales98(1)

Question 305305: Consider the experiment of drawing two cards without replacement from an ordinary deck of 52 playing cards. What are the odds against drawing two spades?
Click here to see answer by Fombitz(13828)

Question 305427: The letters G E O M E T R Y are written on a set of cards. You mix
the cards thoroughly.Without looking, you draw one letter, replace it,
then draw another. Find each probability.
Click here to see answer by Fombitz(13828)

Question 305429: 3. You are visiting Dad’s Root Beer Plant in Oakland. You are asked by the plant supervisor to determine if the Dad’s Brand soda machines are correctly dispensing 32 ounces of root beer. In the past, the equipment was assumed to be not working properly if the cans were over-filled or under-filled. You observe the machine filling 9 bottles and collected the data. You are 95% sure that the machine is filling the bottles correctly. The amount dispersed is assumed to be normally distributed: (T-test)
32.12 32.04 32.04
32.13 32.05 32.05
32.22 31.89 32.20
Click here to see answer by richwmiller(9135)

Question 305440: you suck
Click here to see answer by Fombitz(13828)

Question 305440: you suck
Click here to see answer by Edwin McCravy(8909)

Question 305428: You are given the following information, find the Z-statistic: (95% level of confidence) based on the Z-test
Xbar = 980
U = 1000
Sample stdev = 50
N = 36
Click here to see answer by stanbon(57347)

Question 305400: Two cards are drawn from a standard deck of cards. Find P(both black or both 9's, but not a black 9)
Click here to see answer by edjones(7569)

Question 305398: in how many ways can a study group of four be selected from a class of 24 students?
Click here to see answer by edjones(7569)

Question 305589: The probability of randomly selecting a red marble from a bag, replacing it, and selecting a red marble again is 1/25. What is the probability of selecting a red marble on the first try? explain.
I know the 1/25 is a simplified result, so I am wondering if the first try is 1/5, then the 2nd try is 1/5, multiply across = 1x1 = 1, and 5x5 = 25, this is how I thing the answer is.
Click here to see answer by solver91311(16885)

Question 305605: The probability of randomly selecting a red marble from a bag, replacing it, and selecting a red marble again is 1/25. Suppose you know there are 2 red marbles originally in the bag. How many marbles are in the bag?
Would the answer be 2?
Click here to see answer by solver91311(16885)

Question 305624: What are the possible outcomes for the dice to equal the sum of 6 if rolling three dice. I can only come up with nine but my physics teacher said there are more.
Click here to see answer by solver91311(16885)

Question 305706: example: Two dice are rolled, and the furst die shows a 5. Find the probability of each event below for the two cubes.
Question: a sum of 9
queston: two odd numbers
Click here to see answer by stanbon(57347)

Question 305697: how do you solve the probibilty of 31 flavors, 3 types of cone, with or without 1 of 4 toppings?
Click here to see answer by stanbon(57347)

Question 305698: A clinical trial is planned to compared an experimental mediciation designed to lower blood pressure to a placebo, before starting the trial, a pilot study is conducted involving 10 participants. The objective of the study is to assess how systolic blood pressure change untreated over time. Systolic blood pressure are mesaured at baseline and again 4 weeks later,
Computed 95% confidence interval for the mean difference in blood pressure over 4 weeks.
Baseline: 120 145 130 160 152 143 126 121 115 135

4 weeks: 122 142 135 158 155 140 130 120 124 130

I'm looking for how it solves with 95% for calcuated, It makes confused me formula. using mean -( )*(sqrt/( )?

Gloria

Click here to see answer by stanbon(57347)

Question 305679: Two popular drugs used for the treatment of depression are Resithan and Exemor. A random sample of depressed individuals is selected and treated with Resithan, and find relief from their depression. A random sample of depressed individuals is independently selected from the first sample and treated with Exemor, and find relief from their depression. Can we conclude, at the level of significance, that the proportion of all depressed individuals taking Resithan who find relief from depression is greater than the proportion of all depressed individuals taking Exemor who find relief from depression?

Click here to see answer by stanbon(57347)

Question 305696: A study is run to estimate the mean total cholesterol level in children 2 to 6 years of age. A sample of 9 participants is selected and their total cholesterol levels are measured as follows:
185 225 240 196 175 180 194 147 223
Generate a 95% confidence interval for the true mean total cholesterol level children.
How it solves with 95% formula should be?
Gloria
Click here to see answer by stanbon(57347)

Question 305683: Eight college students were randomly divided into 2 groups of 4 each to test whether background music reduces studying capacity. Each person was tasked with memorizing a list of 20 words. Group 1 had music playing through earphones they were wearing. Group 2 was not distracted. The following are the number of words correctly remembered by each subject. Test whether the music reduces studying capacity at a .05 level of significance.
Group 1 -- DISTRACTED Group 2 – NOT DISTRACTED
Sample mean = 7
Sample size = 4
Sample std.dev. = 2.5 Sample mean = 14
Sample size = 4
Sample std.dev. = 3.5
3a) Direction = UPPER TAILED / LOWER TAILED / 2-TAILED (circle one)
3b) P-value = ________________
3c) REJECT THE NULL or DO NOT REJECT THE NULL? (Circle one)
3d) Can we conclude that music reduces studying capacity? YES or NO (circle one)

Click here to see answer by stanbon(57347)

Question 305673: Another measure of variation is variance, which equals mc005-1.jpg. Find the variance and standard deviation of the data set. Round to the nearest tenth.
3, 9, 11, 8, 7, 3
a) variance = 8.8;
standard deviation = 3
b) variance = 8.8;
standard deviation = 3.3
c) variance = 1.7;
standard deviation = 3.3
d) variance = 1.7;
standard deviation = 3
Really confused on how to find this answer. Thanks for anyone who explains!
Click here to see answer by stanbon(57347)

Question 305807: Monthly utility bills in a certain city are normally distributed with a mean of 100 and a standard deviation of 12. A utility bill is randomly selected.
What is the highest utility bill that can be in the bottom 32% of the bill?
Click here to see answer by stanbon(57347)

Question 305680: ONE SAMPLE HYPOTHESIS TEST FOR PROPORTION: The Webster University librarian believes that more than 60% of the books checked out by students was fictional material. In a random sample of 1000 students who checked books out in the last year, 628 checked out fictional material. What can one conclude about the librarian's hypothesis at a level of significance of .05?
2a) Direction = UPPER TAILED / LOWER TAILED / 2-TAILED (circle one)
2b) P-value = ________________
2c) REJECT THE NULL or DO NOT REJECT THE NULL? (circle one)
2d) Can we conclude the librarian’s claim is correct? YES or NO (circle one)

Click here to see answer by stanbon(57347)

Question 305651: Find a group of of 8 men and 11 women, a committee if 5 is selected at random. Find P(at least 3 men)
Click here to see answer by stanbon(57347)

Question 305601: to open a combination lock, you must dial a 3-digit combination using the digits 0-39. How many combinations are possible ...
a) if repeating a digit is allowed
b) if repeating a digit is not allowed
Click here to see answer by stanbon(57347)

Question 305833: The Gibbs Baby Food Company wishes to compare the weight gain of infants using their brand versus their competitor’s brand. A sample of 40 babies using the Gibbs products revealed a mean weight gain of 7.6 pounds in the first 3 months after birth. The standard deviation of this sample is 2.3 pounds. A sample of 55 babies using the competitors brand revealed a mean increase of 8.8 pounds with a standard deviation of 2.9 pounds. At 95% level of confidence, can we conclude that the babies using the Gibbs product gained LESS weight? Z-test for Unpaired data
Click here to see answer by stanbon(57347)

Question 305950: 3. A fruit basket contains five red apples and three green apples. Without looking, you randomly select two apples. What is the probability that
a) You will select two red apples?
b) You will not select two green apples?
Textbook answers: 3.a)5/14 and 3.b) 25/28
Click here to see answer by Fombitz(13828)

Question 305960: 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 Fombitz(13828)

Question 305941: A jar contains two red and five yellow marbles. A marble is drawn at random and then without replacement, A second draw is made at random. Find the probability that the second marble is red given that the first is yellow.
I have 2 out of 7 to represent the # of red marbles. And because there is no replacement, the second would be 5 out of 6. Using the Fundamental Counting Principal, I multiplied the two probabilities and got 10 out of 42.
My teacher says the answer is 14 out of 42, though. I have to prove whether that statement is right or wrong. Did I do something wrong? Please explain.
Click here to see answer by edjones(7569)

Question 306204: 2. A bag contains two red balls, three blue balls and five green balls. Three balls are drawn at random. Find the probability that
a) the three balls are of different colours.
b) two balls are of the same colour.
c) all the three are of the same colour. 10 marks
Click here to see answer by toidayma(44)

Question 306152: equation with rational expressions solve
x/x+1+6/x+7 , and please
x-3/5=x-3/x
Click here to see answer by stanbon(57347)

Question 306102: A clinical trial is conducted comparing a new pain reliever for arthritis to a placebo. Participants are randomly assigned to receive the new treatment or a placebo. The outcome is pain relief within 30 minutes. The data are shown in table 6-8

Pain relief no Pain relief
New medication 44 76
Placebo 21 99

a. Generate a 95% confidence interval for the proportion of patients on the new medication who report pain relief.
b. Generate a 95 % confidence interval for the difference in proportions of patients who report pain relief.

how it calculated with 30 mins ? I'm still not understand.
Click here to see answer by stanbon(57347)

Question 306089: 13. Hans has 12 good friends, five of them male and seven of them female. He decides to have a dinner party but can invite only seven because his dining room table will seat only eight people. He decides to invite his guestes by lot. What is the probability that
a) There will be four males and four females at the party?
b) Rivka will be among those invited?
c) Hans will have only female guests?
Textbook answers:
13 a)0.44
b) 7/12
c) 1/792
Click here to see answer by stanbon(57347)

Question 306277: How do you write the odds for (or in favor of)? The odds against? Suppose a bag contains ten slips with classroom enrichment tasks you can do for extra credit. The tasks include problems related to probability, geometry, and algebra. The number of tasks related to probability is twice the number of tasks related to algebra. There is at least one task devoted to each type of problem.
1. If the odds of choosing an algebra task are 1 : 9, how many slips for each task will there be?

2. If the odds of choosing an algebra task are 1 : 4, how many slips for each task will there be?

3. If the odds of choosing a probability task are 3 : 2, how many slips for each task will there be?

Click here to see answer by Fombitz(13828)

Question 306291: Find the probabilities.
From National Weather Service records, the annual snowfall in the TopKick Mountains has a mean of 92 inches and a standard deviation s of 12 inches. If the snowfall from 25 randomly selected years are chosen, what it the probability that the snowfall would be less than 95 inches
Click here to see answer by stanbon(57347)

Question 306093: Problem 4, the following data were collected as part of a study of coffee consumption among male and female undergraduate students. The following reflects cups per day consumed.
Male: 3 4 6 8 2 1 0 2
Female: 5 3 1 2 0 4 3 1

Generate a 95% confidence interval for the difference in mean numbers of cups of coffee consumed between men and woman

Click here to see answer by stanbon(57347)

Question 306086: Conside the numbers 2051 over 2050 and 2052 over 2051. Which of the following is true?

2051 2052
2050 > 2051
2051 2052
2050 < 2051
2051 2052
2050 = 2051
None of the above

Click here to see answer by stanbon(57347)

Question 306309: In a 52 card deck, how many ways are there to get 21 in two cards?
Click here to see answer by Fombitz(13828)

Question 306323: There is a box of 22 white and 8 red balls. Eight are picked at random. What is the probability that they are all white?
Click here to see answer by scott8148(6628)

Question 306367: in a certain lottery, 4 different numbers between 1 and 11 inclusive are drawn. These are the winning numbers. A player selects 4 different number between 1 and 11. What is the probability that the player has all the winning numbers?
Click here to see answer by Fombitz(13828)

Question 306311: Find the probabilities.
The loan officer rates applicants for credit. Ratings are normally distributed. The mean is 240 and the standard deviation is 50. Find the probability that an applicant will have a rating greater than 300.
Click here to see answer by Fombitz(13828)

Question 306386: . A math test was given; a sample of the scores yielded the following results:
82, 95, 41, 0, 95, 86, 14, 51, 13, 80, 72, 60, 97, 28, 27, 19
Find the range, standard deviation, and variance for the sample scores
Click here to see answer by Fombitz(13828)

Question 306453: Find the value of the following:

8!12!/5!14!
Click here to see answer by Fombitz(13828)

Question 306453: Find the value of the following:

8!12!/5!14!
Click here to see answer by richwmiller(9135)

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