Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 84213: A focus group of 10 adults was chosen to evaluate the performance of a candidate during a presidential debate. Each member of the group rated the overall performane on a scale of 1 (poor) to 10 (superior). The ratings given the candiates were as follows:
4 5 8 7 9 8 7 3 6 7
Calculate the (a) range (b) mean deviation (c) variance and standard deviation for these rating scores.
Click here to see answer by venugopalramana(3286)  |
Question 84753: The scores for a standardized reading test are found to be normally distributed with a mean of 500 and a standard diviation of 60. If the test is given to 900 students, how many are expected to have scores between 500 and 620?
A)306
b) 432
c)459
d)612
Click here to see answer by Scriptor(36) |
Question 84798: Suppose that you purchase a lottery ticket that contains two numbers and a letter such as
3 7 P
A. What is the probability that you match the first digit?
B. What is the probability that you match the second digit?
C. What is the probability that you do not match the first digit?
D. What is the probability that you match both the first and second digits?
E. What is the probability that you match the letter?
F. what is the probability of a perfect match (both digits and the letter)?
Click here to see answer by bucky(2189) |
Question 84940: IQ scores are normally distributed with a mean u=100 and a standard deviation o=15.
Based on this distribution determine.
A. the percentage of IQ scores between 100 and 120.
B. the probability of selecting a person at random having an IQ between 100 and 120.
C. the percentage of IQ scores between 88 and 100.
D. the probability of selecting a person at random having an IQ between 88 and 100.
E. the percentage of IQ scores that are 110 or above.
F. the probability of selecting a person at random having and IQ of 110 or above
Click here to see answer by Nate(3500) |
Question 84937: Suppose that you purchase a lottery ticket that contains two numbers and a letter, such as
3 7 9
Alright this is what i have so far for #15
A. What is the probability that you match the first?
37P
3P7
73P
7P3
P73
P37
18 chances
So it has two chances of being first.
P= number of times the out come or events can occur
2 divided by 18=.11
B. What is the probability that you match the second digit?
Same thing 18 chances
2 divided by 18=.11
C. What is the probability that you do not match the first digit?
17 divided by 18 =.88 or rounded .89
D. What is the probability that you match both the first and the second digits?
.89 is the answer but i don't know how to get it. please show me the formula.
E.What is the probability that you match the letter?
1 chance divided by 26 letters in the alphabet = .038 or rounded .04
F. What is the probability of a perfect match (both the digits and the letter)?
not sure how to get this one either. please show me the work and the formula
Click here to see answer by stanbon(57307) |
Question 84799: IQ scores are normally distributed with a mean u=100 and a standard deviation o=15.
Based on this distribution, determine
A. the percentage IQ scores between 100 and 120.
B. the probability of selecting a person at random having an IQ between 100 and 120
C. the percentage of IQ scores between 88 and 100.
D. the probability of selecting a person at random having and IQ between 88 and 100.
E. the percentage of IQ scores that 110 or above.
F. the probability of selecting a person at random having an IQ of 110 or above.
Click here to see answer by stanbon(57307) |
Question 84747: The scores for a standardized reading test are found to be normally distributed with a mean of 500 and a standard diviation of 60. If the test is given to 900 students, how many are expected to have scores between 500 and 620?
A)306
b) 432
c)459
d)612
Click here to see answer by stanbon(57307) |
Question 85217: Please help, I do not even know how to set this problem up. I would appreciate any help that you can give me. Thank you so much for your time.
Brenda
Fictional Bob asked his administrative assistant to get a quote on new computer monitors for their department. The administrative assistant, forgetting the mix that Fictional Bob requested, delivers the following two quotes (these quotes exclude taxes and shipping):
Quote #1: four 17”-monitors and six 19”-monitors for $2300
Quote #2: six 17”-monitors and four 19”-monitors for $2200
What are the prices for a single 17”-monitor and a single 19”-monitor?
Click here to see answer by stanbon(57307) |
Question 85488: Suppose that the population standard deviation (o) for a normally distributed standardized test of achievement is known to be 7.20. What would the standard error of the sample mean (o-x)be if we were to draw a random smaple of 16 test scores?
Please help...show the work please.
Click here to see answer by stanbon(57307) |
Question 86026: Can you please help me with this question? This question is from Algebra II, A Beka Book.
Sarah has an average of 92.5 for her 3 science tests. What does she need to make on the 4th test to get a 94% average?
Thank you so much for your help.
Click here to see answer by tutor_paul(490)  |
Question 86026: Can you please help me with this question? This question is from Algebra II, A Beka Book.
Sarah has an average of 92.5 for her 3 science tests. What does she need to make on the 4th test to get a 94% average?
Thank you so much for your help.
Click here to see answer by bucky(2189) |
Question 86018: Can you please help me with this statistics question. I looked at the answer to question 84214, but was still not sure where to start. This question is from Algebra II, A Beka Book.
Keith's long jump distances in feet from the last 3 track meets: 23.8, 23.0, 22.6, 24.2, 23.8, 22.5, 23.1, 24.0.
How do you find the
a)mean, b) median, c) mode, d)range, e) standard deviation.
Thank you so much for your help.
Click here to see answer by jim_thompson5910(28555) |
Question 86027: Can you please help me with this question? It is from Algebra II, A Beka Book.
The athletic director has 6 trophies won by school teams this year, but only enough space in the trophy case to display 3 at a time. How many different ways can he display the trophies if order is important? Thank you so much for your help.
Click here to see answer by stanbon(57307) |
Question 85999: Can you please help me with this probability question. It is from textbook Algebra II by A Beka Book. I tried to use the solution provided for question 83651 but couldn't solve it.
In a sample bag of M&M's candy, there are 5 brown, 6 yellow, 4 blue, 3 green, and 2 orange.
What is the probability of getting-
a)1 green M&M if only 1 is taken at a time?
b)3 yellow M&M's if 3 are taken at a time?
c)1 brown and 2 orange M&M's if 3 are taken at a time?
Thank you so much for your help!
Click here to see answer by stanbon(57307) |
Question 86311: The national average for the verbal portion of the College Board's SAT is 507. The College Board periodically rescales the test scores such that the standard deviation is approximately 100. Answer the following questions using a bell-shaped distribution and the empirical rule for the verbal test scores.
a. What percentage of students have an SAT verbal score greater than 607?
b. What percentage of students have an SAT verbal score greater than 707?
c. What percentage of students have an SAT verbal score between 407 and 507?
d. What percentage of students have an SAT verbal score between 307 and 607?
Click here to see answer by stanbon(57307) |
Question 86395: A computer store has 10 copies of a word processing program. 12 copies of a spread sheet program, and 8 copies of a drawing program. Three of the word processing, four of the spread sheet, and two of the drawing program are infected with a virus. If a program is selected at randow, the probability it is infected with a virus is?
A. 11/30
B. 7/30
C. 3/10
4. 1/4
Click here to see answer by stanbon(57307) |
Question 86398: In a binomial distrubution, the probability of 25 successes, where n=65 and p=0.35 is..
A. C(65,25)(o.35)^25 (o.15)^40
B. C(65,25)(0.35)^25 (0.65)^40
C. C(65,25)(0.35)^40 (0.65)^25
D. C(65,25)(0.35)^25
Click here to see answer by stanbon(57307) |
Question 86575: i NEED HELP UNDERSTANDING THESE PROBLEMS...CAN SOMEONE HELP ME THANKS.
write out the sample space, and then write the
indicated events in set notation.
An unprepared student takes a three-question, true/false quiz in which he guesses the
answers to all three questions, so each answer is equally likely to be correct or wrong.
a. The student gets three answers wrong.
b. The student gets exactly two answers correct.
c. The student gets only the first answer correct.
pROBLEM #2
A single fair die is rolled. Find the probabilities of each event.
Getting any number except 3
Click here to see answer by stanbon(57307) |
Question 86574: CAN YOU HELP ME UNDERSTAND HOW TO SOLVE THESE THANKS...
pROBLEM #22
Use the union rule to answer the following questions.
Investment Survey Most mathematics professors love to
invest their hard-earned money. A recent survey of 150
math professors revealed that
111 invested in stocks;
98 invested in bonds;
100 invested in certificates of deposit;
80 invested in stocks and bonds;
83 invested in bonds and certificates of deposit;
85 invested in stocks and certificates of deposit;
9 did not invest in any of the three.
How many mathematics professors invested in stocks and
bonds and certificates of deposit?
Click here to see answer by scianci(186) |
Question 86570: Can someone help me please explain it to me towards these problems. If you can and have a few minutes thanks...for your help
PROBLEM #32
Is it possible for two nonempty sets to have the same intersection and union? If so,
give an example.
pROBLEM #64
Electoral College U.S. presidential elections are decided
by the Electoral College, in which each of the 50 states,
plus the District of Columbia, gives all of its votes to a candidate.†
Ignoring the number of votes each state has in the
Electoral College, but including all possible combinations
of states that could be won by either candidate, how many
outcomes are possible in the Electoral College if there are
two candidates? (Hint: The states that can be won by a candidate
form a subset of all the states.)
Click here to see answer by stanbon(57307) |
Question 86613: I need help with these problems if someone has time to help me explain them to me step by steps thanks.
Problem #1
Breast Cancer To explain why the chance of a woman
getting breast cancer in the next year goes up each year,
while the chance of a woman getting breast cancer in her
lifetime goes down, Ruma Falk made the following analogy.†
Suppose you are looking for a letter that you may
have lost.You have 8 drawers in your desk. There is a probability
of .1 that the letter is in any one of the 8 drawers,
and a probability of .2 that the letter is not in any of the
drawers.
a. What is the probability that the letter is in drawer 1?
b. Given that the letter is not in drawer 1, what is the probability
that the letter is in drawer 2?
c. Given that the letter is not in drawer 1 or 2, what is the
probability that the letter is in drawer 3?
d. Given that the letter is not in drawers 1–7, what is the
probability that the letter is in drawer 8?
e. Based on your answers to parts a–d, what is happening
to the probability that the letter is in the next drawer?
f. What is the probability that the letter is in some drawer?
g. Given that the letter is not in drawer 1, what is the probability
that the letter is in some drawer?
h. Given that the letter is not in drawer 1 or 2, what is the
probability that the letter is in some drawer?
i. Given that the letter is not in drawers 1–7, what is the
probability that the letter is in some drawer?
j. Based on your answers to parts f–i, what is happening to
the probability that the letter is in some drawer?
Click here to see answer by Edwin McCravy(8908)  |
Question 86639: Can someone help me with these problems thanks..
Problems #1
Using venn diagram
Let P(Z) = 0.42
P(Y) = 0.35
P (Z U Y) = 0.61
fIND EACH PROBABILITY:
a) P(Z' (UPSIDE DOWN U) Y')
b) P(Z' U Y')
c) P(Z' U Y)
d) P(Z (UPSIDE DOWN U) Y')
Click here to see answer by stanbon(57307) |
Question 86638: Can someone help me with these problems how to solve them..thanks
Problem #1
If two cards are drawn without replacement from an ordinary deck, find the probabilities of the following results.
The second is black, given that the first is a spade.
Problem #2
Pam Snow invites 10 relatives to a party: her mother, 2 aunts, 3 uncles, 2 brothers, 1 male cousin, and 1 female cousin. If the chances of any one guest arriving first are equally likely, find the probabilities that the first guest to arrive is as follows.
a. An uncle or a cousin
b. A male or a cousin
c. A female or a cousin
Click here to see answer by stanbon(57307) |
Question 86637: I need help understanding how to solve these problems...
Problem #1
Let A and B be independent events with P(A) = (1)/(4) and P(B) = (1)/(5)
Find P (A (An upside down letter U) B) and P (A U B).
Problem #2
In the previous section, we described an experiment in which the numbers 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
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 stanbon(57307) |
Question 86634: Any help would be greatly appreciated.....
The following puzzler was given on the Car Talk radio program on February 19, 2001.* “Three different numbers are chosen at random, and one is written on each of three slips of paper. The slips are then placed face down on the table. The objective is to choose the slip upon which is written the largest number. Here are the rules: You can turn over any slip of paper and look at the amount written on it. If for any reason you think this is the largest, you’re done; you keep it. Otherwise you discard it and turn over a second slip. Again, if you think this is the one with the biggest number, you keep that one and the game is over. If you don’t, you discard that one too. . . . The chance of getting the highest number is one in three. Or is it? Is there a strategy by which you can improve the odds?”
The answer to the puzzler is that you can indeed improve the probability of getting the highest number by the following strategy. Pick one of the slips of paper, and after looking at the number, throw it away. Then pick a second slip; if it has a larger number than the first slip, stop. If not, pick the third slip. Find the probability of winning with this strategy.
Click here to see answer by bucky(2189) |
Question 86635: Can someone correct this for me please....thanks
Problem #1
A marble is drawn from a box containing 3 yellow, 4 white, and 8 blue marbles. Find the odds in favor of drawing the following.
a. A yellow marble
My answer 3/15
b. A blue marble
my answer 4/15
c. A white marble
My answer 8/15
Problem #2
. Body Types A study on body types gave the following
results: 45% were short; 25% were short and overweight;
and 24% were tall and not overweight. Find the probabilities
that a person is the following.
a. Overweight
b. Short, but not overweight
c. Tall and overweight
Click here to see answer by stanbon(57307) |
Question 86633: can someone help me understand how to solve this type of problems thanks...
Problem #1
Using the union rule to answer the following questions.
suppose n(A (A LETTER "u" UPSIDE DOWN) b) = 5
n(A U B) = 35
n (A) = 13
what is n(B)?
Problem #2
Show that the stamtements is true by drawing venn diagrams and shading the regions representing the sets on each side of the equals sign.
(A (UPSIDE DOWN U) B)' = A' U B'
Click here to see answer by stanbon(57307) |
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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
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