Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 257551: Conditional Probability. (Tree diagram ?)
In a World Series, teams A and B play until one team wins four games. Suppose all games are independent and that on each game, the probability that team A beats team B is 3/5.
(a) What is the probability that team A wins the series?
(b) What is the probability that team A wins the series in five games?(c) You know that team A wins the series. What is the expected number of games they play?
(d) What is the probability the team that wins the first game will win the series?
Click here to see answer by edjones(7569)   |
Question 257717: Conditional Probability. (Tree diagram ?)
I really don't understand where i have to start, What is a tree diagram and how do i solve this question by tree diagram ? HELP PLEASE !!!
In a World Series, teams A and B play until one team wins four games. Suppose all games are independent and that on each game, the probability that team A beats team B is 3/5.
(a) What is the probability that team A wins the series?
(b) What is the probability that team A wins the series in five games?(c) You know that team A wins the series. What is the expected number of games they play?
(d) What is the probability the team that wins the first game will win the series?
Click here to see answer by edjones(7569) |
Question 257840: Mr Jones invests money in stocks that earns a 6% return and bonds that earn a 8% return. He invests three times as much money in stocks as bonds. If he earns $900 annual interest, what is the total amount of money invested?
Click here to see answer by stanbon(57342) |
Question 257886: Dear Tutor,
according to officials of Mars, the makers of m & m candies, 20% of the candies in each bag are red four candies are selected from a bag and the number of red candies are recorded find the expected value.
I know that the answer is 8, but I do not know the formula.
Click here to see answer by edjones(7569) |
Question 257929: 2) The type of people watching a film at a cinema is shown in the table.
----------Male---Female
Adult-----21------14
Child-----10------5
Two of these people are chosen at random to receive free cinema tickets.
Calculate the probability that two chosen people are adults of the same gender.
Click here to see answer by stanbon(57342) |
Question 257875: To encourage telephone efficiency, a catalog call center issues a guideline that at least half of all telephone orders should be completed within 2 minutes. Subsequently, a random sample of 64 telephone calls showed that 40 calls lasted over 2 minutes. (a) At α = .05 is this a significant departure from the guideline in a right-tailed test? State your hypotheses and decision rule. (b) Find the p-value. (c) Is the difference important (as opposed to significant)?
Click here to see answer by stanbon(57342) |
Question 257944: A factory manager surveys the owners of the cars parked in the car park. One of the question is:
"when you drive to work how many people including yourself are in your car?"
The responses are summarised in the table below.
Number of people
1
2
3
4
5
6
Number of cars
42
26
12
2
0
1
Total 83
Calculate the mean number of people per car
Click here to see answer by Greenfinch(383)  |
Question 258071: you spin a spinner numbered 1 through 10. Each outcome is equally likely. Express the probabilities below as a fraction and percent.
1) p(9)-greater than 0
2) p(even)
3) p(number)
another queation:
The U.S Senate has 435 memebers. Each memeber's name is put into a basket and one name is choosen at random. Find each probability as a decimal to the nearest hundreth.
Florida-25
Maryland-19
Texas-19
Virginia-32
1) P(Florida
2) P(Maryland)
3) P(not Texas)
4) P(Virginia
Click here to see answer by stanbon(57342) |
Question 258078: A bag conatains
5 green skittles
3 red skittles
2 orange skittles
6 yellow skittles
how many green skittles must be added to the bag so that the probability of radomly picking a green skittle is 2/3? explain.
another question:
Twelve out of the 144 Shoe City Stores sell childrens clothing. You write the names of all the store locations on cards and select a card at random.
What is the probability of not picking a store location that sell children's clothing? JUSTIFY
Click here to see answer by stanbon(57342) |
Question 258182: Can you please help me with this problem?
The average mpg usage for a 2004 Ford Expedition 2WD for a sample of 10 tanks of gas was 17.0 with a standard deviation of 0.8. For a Ford Explorer 2WD, the average mpg usage for a sample of 10 tanks of gas was 18.5 with a standard deviation of 1.0.
a) What are the null and alternative hypotheses to test if the 2004 Ford Expedition has lower fuel economy than the 2004 Ford Explorer?
b) Using α = 0.01, what is the critical value for the hypothesis test?
c) What is the test statistic for the hypothesis test?
d) Draw a conclusion for the hypothesis test. Make sure you state your conclusion in the context of the problem.
e) What is the p-value for the hypothesis test?
Your Help is very much appreciated.
Click here to see answer by stanbon(57342) |
Question 258242: Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions during the next year, yielding a sample mean of 14.44 with a standard deviation of 4.45 pages. (a) At the .01 level of significance, is the true mean greater than 10? (b) Use Excel to find the right-tail p-value.
Click here to see answer by stanbon(57342) |
Question 258127: Out of 2 million hay fever sufferers, 20% are allergic to tree pollen. If 11 hay fever victims are picked at random what is the probability that 5 have tree pollen what is the probability that 7 have tree pollen,what is the probability that none have tree pollen allergy and what is the probabiltiy that at least one has tree pollen allergy? Any help with this would be greatly appreciated.
Thanks Susan
Click here to see answer by edjones(7569) |
Question 258292: A bag contains two different colors of ribbons
There are 3 black and 12 green ribbons.
Lila selects a ribbon at random then jess
Selects a ribbon from the remaining ribbons
What is the prpbability that lila selects a black
And jess selects a green?
Answer in simplest form as a decimal and please explain
So I can solve the other nine on my own
4/25
6/35
11/70
4/35
Thanks
Click here to see answer by edjones(7569) |
Question 258280: Thirteen playing cards, ace through king, are placed randomly with faces down on a table. The prize for guessing correctly the face of any given card is $5. What would be a fair price to pay for a guess?
AND
A department store wants to sell 13 purses that cost the store 50 dollars each and 30 purses that cost the store 10 dollars each. If all purses are wrapped in 43 identical boxes and if each customer picks a box randomly, find the department store's expected profit if it charges 20 dollars for each box
AND
A box contains 3 defective bulbs and 10 good bulbs. If 6 bulbs are drawn from the box without replacement, what is the expected number of defective bulbs?
Click here to see answer by edjones(7569) |
Question 258309: Airlines find that each passenger who reserves a seat fails to turn up with probability 1/10 independently of the other passengers. So Teeny Weeny Airlines always sell 10 tickets for their 9 seat aeroplane while Blockbuster Airways always sell 20 tickets for their 18 seat aeroplane. Which is more often over-booked?
Click here to see answer by Theo(3463)  |
Question 258357: The probability of drawing a green marble from a marble bag is 80%. What are the odds in favor of drawing a green marble?
A. 1:4
B. 4:5
C. 4:1
D. 5:4
I know this easy but I cannot figure out how to do this anymore. Please explain how to do this.
Also do you know what they mean with "Sample Space" dealing with a pie chart and probability?
Click here to see answer by richwmiller(9135)  |
Question 258378: (By way of conditional probability)
Urn A contains 2 white and 4 red balls, whereas urn B contains 1 white and 1 red ball. A ball is randomly chosen from urn A and put in urn B, and a ball is then randomly selected from urn B.
(a) What is the probability that the ball selected from urn B is white?
(b) What is the conditional probability that the transferred ball was white given that a white ball is selected from urn B?
Click here to see answer by edjones(7569) |
Question 258325: Eight pawns are placed randomly on a chessboard, no more than one to a square. What is the probability that:
(a) they are in a straight line (do not forget the diagonals)?
(b) no two are in the same row or column?
Click here to see answer by edjones(7569) |
Question 258547: The probability of rain on July 4th in Chicago is 0.35. The probability of snow in Chicago on January 1st is 0.4. What is the probability that it will either rain on July 4th or snow on January 1st in Chicago (but not both)?
Click here to see answer by drk(1908) |
Question 258567: if there is a standard deck of 52 cards, what is the probability of getting a king and a diamond?
probability of getting a king or a diamond?
probability of getting a club, then a spade?
probability of getting a face vard, then a 6?
Click here to see answer by stanbon(57342) |
Question 258305: On a standard measure of hearing ability, the mean is 300 and the standard deviation
is 20. Give the Z scores for persons who score (a) 340, (b) 310, and
(c) 260. Give the raw scores for persons whose Z scores on this test are (d) 2.4,
(e) 1.5, (f) 0, and (g)-4.5.
Click here to see answer by stanbon(57342) |
Question 258730: A candidate got interview calls from6 Institutes of Management. Assume that his chance of getting admission in each of the Institute is 0.25. Assume each institute conducts separate interview process and results are independent of each other. What is the probability that the candidate will get admission in at least 3 institutes?
Click here to see answer by Theo(3463) |
Question 258722: Normal Distribution
The scores for the intelligence quotient (IQ) test are normally distributed with mean 100 and standard deviation 16.
(a) What is the probability that at least two of five randomly selected people have IQ test score higher than 120?
(b) A person is randomly selected from all people whose IQ are higher than 110. What is the probability that this person has IQ higher than 120?
(c) One thousand people are randomly selected. Approximately what is the probability that fewer than 90 of them have IQ score higher than 120?
Click here to see answer by stanbon(57342) |
Question 243056: Refer to the CIA data, which report demographic and economic information on 46 countries.
a. The mean of the GDP/capita variable is 16.58 with a standard deviation of 9.27. Use the normal distribution to estimate the percentage of the countries with exports above 24. Compare this estimate with the actual proportion. Does the normal distribution appear accurate in this case? Explain.
b. The mean of the exports is 116.3 with a standard deviation of 157.4. Use the normal distribution to estimate the percentage of countries with exports above 170. Compare this estimate with the actual proportion. Does the normal distribution appear accurate in this case? Explain.
Can someone give me the steps how to set this up in excel? I don't necessarily need the answer to the question as much as I need the steps to create it in excel. The book is "Basic Statistics for Business & Economics" 6th edition. Thank you.
Click here to see answer by 66171(1) |
Question 258784: Amniocentesis tests result in miscarriage 0.5% of the time. Assuming each test is independent and follows a Bernoulli random variable, then what is the variance of one test? What is the variance of 400 tests? I found the equation for variance p(1-p), but it doesn't take into account the number of tests.
Click here to see answer by stanbon(57342) |
Question 258838: A certain airplane has two independent alternators to provide electrical power. The probability that a given alternator will fail on a one-hour flight is .02. What is the probability that (a) both will fail? (b) Neither will fail? (c) One or the other will fail? Show all steps carefully.
Click here to see answer by Fombitz(13828)  |
Question 259029: The loan officer rates applicants for credit. Ratings are normally distributed. The mean is 240 and the standard deviation is 30. If 36 applicants are randomly chosen, what is the probability that they will have a rating between 230 and 260?
Click here to see answer by stanbon(57342) |
Question 259106: 6. A survey of 100 MBA students found that 60 owned mutual funds, 40 owned stocks, and 20 owned both.
a. What is the probability that a student owns a stock? A mutual fund?
probability
mutual 60 0.6
stocks 40 0.4
b. What is the probability that a student owns neither stocks nor mutual funds?
i.
c. What is the probability that a student owns either a stock or a mutual fund?
i.
Click here to see answer by stanbon(57342) |
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