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

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

Question 445456: One thousand raffle tickets are sold for $5.00 each. One grand prize of $1000 and two consolation prizes of $200 each will be awarded. Jeremy purchases one ticket. Find his expected value. Show your work for full credit.
Click here to see answer by Edwin McCravy(8907)

Question 445458: The theoretical probability of undesirable side effects resulting from taking Grebex is 1 in 20. If 100 people take Grebex to lower their blood pressure, how many will encounter undesirable side effects?
Click here to see answer by ewatrrr(10682)

Question 445449: If P(A) = 0.20, P(B) = 0.40 and P(A and B) = 0.08, then A and B are:

A. dependent events

B. independent events

C. mutually exclusive events

D. complementary events

Click here to see answer by ewatrrr(10682)

Question 445470: The average years of employee experience at a company with 10,000 employees is normally distributed, with a standard deviation of 12 years. If a sample of 50 employees indicates a mean age of 38, calculate 90 percent and 99 percent confidence intervals for the population mean.
Click here to see answer by ewatrrr(10682)

Question 445476: Which pair has equally likely outcomes? Check the 2 choices below which have equal probabilities of success. A standard deck of cards has 12 face cards and four aces. (Aces are not face cards).
*Rolling a sum of 9 on two fair six sided dice.
*Drawing the queen of diamonds out of a standard 52 card deck given it's a face card.
*Rolling a sum of 11 on two fair six sided dice.
*Drawing a king out of a standard 52 card deck given it's a face card.
*Rolling a sum of 10 on two fair six sided dice.
Click here to see answer by ewatrrr(10682)

Question 445446: If A and B are mutually exclusive events with P(A) = 0.40, then P(B):

A. can be any value between 0 and 1.

B. cannot be larger than 0.40.

C. cannot be larger than 0.60.

D. cannot be determined with the information give.

Click here to see answer by rajagopalan(158)

Question 445502:
The formula for the area of circle is A= pi.r^2 .(page 395# 28)

Find the inverse of the funtion
Click here to see answer by nerdybill(6958)

Question 445506: Each of the numbers 0 through 14 is written on a piece of paper and all of the pieces of paper are placed in a hat. One number is selected at random. Determine the probability that the number selected is even.
*8/15
*1/2
*3/7
*6/15
Click here to see answer by ewatrrr(10682)

Question 445510: For a game,Patricia must roll a die and draw a card from a deck of 26 cards, with each one having a letter of the alphabet on it .What is the probability that Pateicia will roll an odd number and draw a letter in her name?
.(page 401# 35)

The key is: 3/26
Click here to see answer by ewatrrr(10682)

Question 445501: An object is accelerating at 50 feet second squared.How fast is it accelerating in meters per second squared?(page 394# 7)
The key is: 15.24m/s^2

Click here to see answer by ewatrrr(10682)

Question 445511: Given an experiment of drawing two cards from a standard deck of 52 where the first card is not replaced before the second card is drawn:
Click here to see answer by stanbon(57307)

Question 445494: Write equation in quadric form
http://i1142.photobucket.com/albums/n608/nancylam67/Page37028.jpg
http://i1142.photobucket.com/albums/n608/nancylam67/IMG.jpg
I Appreciate to help my home work
Click here to see answer by ewatrrr(10682)

Question 445516: A safety light is designed so that the times between flashes are normally distributed with a mean of 4.00 seconds and a standard deviation of .50 seconds.
a. Find the probability that an individual time is greater than 4.50 seconds
b. Find the probability that the mean for 50 randomly selected times is greater than 4.50 seconds
c. Is part a or b more significant (being light) due to the importance of a sample OR SINGLE strobe?
Click here to see answer by stanbon(57307)

Question 445484: evaluate: C
8 3

Need help in how to calculate this.
Click here to see answer by stanbon(57307)

Question 445525: If a license plate consists of 3 letters followed by 3 numbers that may be repeated, how many number plates may have at least one 3?
Click here to see answer by jorel1380(2518)

Question 445561: In a scale drawing of a house, the living room is 1 in. long. The actual length is 24 ft.
On the drawing, a hallway is 1/4 in. wide. Find the actual width.

Click here to see answer by Alan3354(30993)

Question 445562:

Write a proportion to solve: A student types 120 words in 3 min and x words in 5 min. Find x.

Click here to see answer by nerdybill(6958)

Question 445559: In a scale drawing of a house, the living room is 1 in. long. The actual lenght is 24 ft.
The actual width of the living room is 18 ft. Find the width on the drawing.

Click here to see answer by checkley79(3050)

Question 445557: Suppose you select a marble at random from a jar containing 3 green, 2 red, and 5 blue marbles. Find each probability.
not selecting a red marble

Click here to see answer by checkley79(3050)

Question 445663: A single die rolled. What is the probability that the number on top is the following:
a. A 3 b. An odd number
c. A number less than 5 d. A number greater than 3

Click here to see answer by rfer(12657)

Question 445831: IQ scores in a general adult population have mean 100 and standard deviation 15. A simple random sample of 50 adults is selected, and the sample mean x of their IQ scores is computed.
What is the probability that the sample mean IQ score is greater than 105.0? Give your answer as a number between 0 and 1, rounded to 3 decimal places.
Click here to see answer by stanbon(57307)

Question 445783: There are six purple socks and 4 orange socks in a drawer. Zucky picked one sock without looking and then another with out looking or replacing the first. What is the probability that he picked two purple socks.
Click here to see answer by stanbon(57307)

Question 445768: Suppose a quantity is halved every 18 years. Use the approximate half-life formula to estimate its decay rate.
Click here to see answer by stanbon(57307)

Question 445764: If the doubling time of a state’s population is 42 years, how long does it take for the population to increase by a factor of 16?
Click here to see answer by stanbon(57307)

Question 445722: Alicia is going to the state fair this weekend. one of the games of chance that she enjoys is called " mouse trap". To play mouse trap , you must predict the color of the hole in which a mouse runs into after a bell is rung. If there are 20 different colored holes, what is the probability that Alicia wins two games in a row?
Click here to see answer by stanbon(57307)

Question 445850: 1.Karen wants to perform a test of hypothesis using α = 0.05 to test H0: μ = 73 and Ha: μ ≠ 73. What value of z should she use to form the rejection region(s)?
A z < -1.28
B z > 1.28
C z < -1.645
D z > 1.645
E z < -2.33
F z > 2.33
G z < -1.645 or z > 1.645
H z < -1.96 or z > 1.96
I z < -2.575 or z > 2.575
J none of the above
2Harry wants to perform a test of hypothesis using α = 0.1 to test H0: μ ≤ 73. What value of z should he use to form
the rejection region(s)?
A z < -1.28
B z > 1.28
C z < -1.645
D z > 1.645
E z < -2.33
F z > 2.33
G z < -1.645 or z > 1.645
H z < -1.96 or z > 1.96
I z < -2.575 or z > 2.575
J none of the above
3.Adam has performed a hypothesis test and concluded that his p-value is .0175. Assume α = .01. Should he
reject his null hypothesis?
A reject
B do not reject
4. Shirley has performed a hypothesis test and concluded that her p-value is .0175. Assume α = .05. Should she
reject her null hypothesis?
A reject
B do not reject
5.In general, what is the value of having a p-value?
A it lets the user decide what alpha to use, and then decide whether to reject (or not reject) the null hypothesis
B it forces the user to use a given alpha when deciding whether to reject (or not reject) the null hypothesis
C it has no particular value; it is just a confusion factor
D it lets the user decide what alpha to use, and then choose a confidence level
E none of the above
Click here to see answer by stanbon(57307)

Question 445714: a teacher gives a 6 question true false quiz. If a students guesses on each question, how many different ways could the 6 questions be answered?
Click here to see answer by stanbon(57307)

Question 445869: A student claims that if a coin is tossed and comes up heads 5 times in a row, then, according to the law of averages, the probability of tails on the next toss is greater than the probability of heads. What is your reply?
Click here to see answer by edjones(7569)

Question 445878: In a recent season, Monique Currie of the Duke Blue Devils scored 635 points. She made a total of 356 shots, including 3 point field goals, 2-point field goals, and 1-point free throws. She made 76 more 2-point field goals than free throws and 77 more free throws than 3-point field goals. Find the number of each type of shot she made.
Appreciate if someone can help.

Click here to see answer by josmiceli(9669)

Question 445967: Robert has 11 red folders, 5 blue folders, 13 green folders, and 9 black folders on his shelf.
If he randomly grabs a folder, what is the probability that it will be either green or black?

Click here to see answer by stanbon(57307)

Question 445993: The participants in a television quiz show are picked from a large pool of applicants with approximately equal numbers of men and women. Among the last 10 participants there have been only 2 women. If participants are picked randomly, what is the probability of getting 2 or fewer women when 10 people are picked?

Click here to see answer by stanbon(57307)

Question 445883: in taking a survey, is there any statistical theory or formular that can be used to determine the number of population which 44 sample size represent?
Click here to see answer by stanbon(57307)

Question 445716: The property restoration company PuroServ is considering switching to new dehumidifiers. Their market research, considering the cost of the new machines and their efficiency, tells them that the switch would give them an 80% chance of making a $20,000 profit, a 15% chance of breaking even,and a 5% chance of losing $5,000. How much money does PuroServ expect to make with their new purchase
Click here to see answer by stanbon(57307)

Question 446000: Can someone please help I have never done this before and I have been out of school for over 10 years. Please Help!!!!!!!!!!!!!!!!
given that P(A) = 0.3 and P(B) = 0.9, and P(A and B) = 0.18, determine P(B|A).
a) 0.30
b) 0.60
c) 0.15
d) 0.20
Click here to see answer by ewatrrr(10682)

Question 446013: Hi, I'm stuck with this question, please help me :(
An economist wishes to estimate the average family income in a certain population. The population standard deviation is known to be $4,500 ; and the economist uses a random sample of size n=225. What is the probability that the sample mean will fall within $800 of the population mean?
Thanks you !
Click here to see answer by ewatrrr(10682)

Question 446014: for each hypothesis listed indicate:
Whether the appropriate analysis would be a one-tailed test or a two-tailed test.
A type I and type II error, given the context of the hypothesis.
Hypothesis:
The three treatments tested differ in how well they work.
Children receiving supportive therapy will get worse over time (at posttreatment).
Girls will do better than boys with treatment (any treatment).

Click here to see answer by stanbon(57307)

Question 445963: 1 Alpha and Confidence Level are related by a simple rule. What is that rule?
A 0.0 <= p(alpha) <= 1.0
B 0.0 <= (Confidence Level + alpha) <= 1.0
C (Confidence Level + alpha) = 1.0
D (Confidence Level - alpha) = 1.0
E none of the above
2 “The Scientific Method” is based largely on what statistical tool (or method)?
A Measures of Location and Variation
B Confidence Intervals
C Rules of Probability
D Hypothesis Tests
E none of the above
3 When writing a Null Hypothesis, we always follow a
A conservative approach
B liberal approach
C scientific approach
D mathematical approach
E none of the above
4 The Null Hypothesis and the Alternate Hypothesis are always written so that they divide the number scale (or Universe) into how many pieces?
A 0 or 1
B 2
C 3
D 2 or 3
E more than 3
5 After conducting a test of hypothesis, Shelly concluded that she should reject the Null Hypothesis. She must now
A repeat the experiment using the same sample
B repeat the experiment using a different sample
C accept the Null Hypothesis
D accept the Alternate Hypothesis
Click here to see answer by stanbon(57307)

Question 446029: A union of restaurant and foodservice workers would like to estimate this year's mean hourly wage, , of foodservice workers in the U.S. Last year's mean hourly wage was , and there is reason to believe that this year's value is less than last year's.
The union decides to do a statistical test to see if the value has indeed decreased. The union chooses a random sample of this year's wages, computes the mean of the sample to be , and computes the standard deviation of the sample to be .
Questions:
1. what are the null hypothesis and the alternative hypothesis that should be used for the test?
2. In the context of this test, what is a TYPE II error?
3. Suppose that the union decides to reject the null hypothesis. What sort of error might it be making?
Thank you.
Click here to see answer by stanbon(57307)

Question 445860: 1 Alpha and Confidence Level are related by a simple rule. What is that rule?
A 0.0 <= p(alpha) <= 1.0
B 0.0 <= (Confidence Level + alpha) <= 1.0
C (Confidence Level + alpha) = 1.0
D (Confidence Level - alpha) = 1.0
E none of the above
2 “The Scientific Method” is based largely on what statistical tool (or method)?
A Measures of Location and Variation
B Confidence Intervals
C Rules of Probability
D Hypothesis Tests
E none of the above
3 When writing a Null Hypothesis, we always follow a
A conservative approach
B liberal approach
C scientific approach
D mathematical approach
E none of the above
4 The Null Hypothesis and the Alternate Hypothesis are always written so that they divide the number scale (or Universe) into how many pieces?
A 0 or 1
B 2
C 3
D 2 or 3
E more than 3
5 After conducting a test of hypothesis, Shelly concluded that she should reject the Null Hypothesis. She must now
A repeat the experiment using the same sample
B repeat the experiment using a different sample
C accept the Null Hypothesis
D accept the Alternate Hypothesis
E none of the above
Click here to see answer by stanbon(57307)

Question 445857: 1 Alpha and Confidence Level are related by a simple rule. What is that rule?
A 0.0 <= p(alpha) <= 1.0
B 0.0 <= (Confidence Level + alpha) <= 1.0
C (Confidence Level + alpha) = 1.0
D (Confidence Level - alpha) = 1.0
E none of the above
2 “The Scientific Method” is based largely on what statistical tool (or method)?
A Measures of Location and Variation
B Confidence Intervals
C Rules of Probability
D Hypothesis Tests
E none of the above
3 When writing a Null Hypothesis, we always follow a
A conservative approach
B liberal approach
C scientific approach
D mathematical approach
E none of the above
4 The Null Hypothesis and the Alternate Hypothesis are always written so that they divide the number scale (or Universe) into how many pieces?
A 0 or 1
B 2
C 3
D 2 or 3
E more than 3
5 After conducting a test of hypothesis, Shelly concluded that she should reject the Null Hypothesis. She must now
A repeat the experiment using the same sample
B repeat the experiment using a different sample
C accept the Null Hypothesis
D accept the Alternate Hypothesis
E none of the above
Click here to see answer by stanbon(57307)

Question 445670: An aquarium at a pet store contains 40 orange sword fish (22 female and 18 males) and 28 green swordfish (12 females and 16 males). You randomly net one of the fish:
a. What is the probability that it is an orange swordfish?
b. What is the probability that it is a male fish?
c. What is the probability that it is an orange female swordfish?
d. What is the probability that it is a female or a green swordtail?
e. Are the events “male” and “female” mutually exclusive? Explain
f. Are the events “male” and “swordfish” mutually exclusive? Explain

Click here to see answer by stanbon(57307)

Question 446139: of all 3 to 5 year old children, 56% are enrolled in school. If a sample of 500 such children is randomly selected, find the probability that at least 250 will be enrolled in school.
Click here to see answer by stanbon(57307)

Question 446124: The 5 participants in a 200-meter dash had the following finishing times (in seconds): 29, 25,25,31,25
Assuming that these times constitute an entire population, find the standard deviation of the population. Round your answer to at least two decimal places.
I really need help with this kind of math. Could you show me how to work this problem?
Click here to see answer by stanbon(57307)

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