A rare form of malignant tumor occurs in 11 children in a million, so its probability is 0.000011. Four cases of this tumor occurred in a certain town, which had
15915 children.
a. Assuming that this tumor occurs as usual, find the mean number of cases in groups of
15915 children.
b. Using the unrounded mean from part
(a),
find the probability that the number of tumor cases in a group of
15915
children is 0 or 1.
c. What is the probability of more than one case?
d. Does the cluster of four cases appear to be attributable to random chance? Why or why not?
a. The mean number of cases is
?
(Type an integer or decimal rounded to three decimal places as needed.)
b. The probability that the number of cases is exactly 0 or 1 is
?
(Round to three decimal places as needed.)
c. The probability of more than one case is
?
(Round to three decimal places as needed.)
d. Let a probability of 0.05 or less be "very small," and let a probability of 0.95 or more be "very large". Does the cluster of four cases appear to be attributable to random chance? Why or why not?
A.
No, because the probability of more than one case is very small.
Your answer is correct.
B.
Yes, because the probability of more than one case is very small.
C.
Yes, because the probability of more than one case is very large.
D.
No, because the probability of more than one case is very large.
In: Statistics and Probability
According to an airline, flights on a certain route are on time 85% of the time. Suppose 25 flights are randomly selected and the number of on-time flights is recorded.
(a) Explain why this is a binomial experiment.
(b) Find and interpret the probability that exactly17 flights are on time.
(c) Find and interpret the probability that fewer than17 flights are on time.
(d) Find and interpret the probability that at least 17 flights are on time.
(e) Find and interpret the probability that between 15 and 17 flights, inclusive, are on time.
(a) Identify the statements that explain why this is a binomial experiment. Select all that apply.
A.There are three mutually exclusive possibly outcomes, arriving on-time, arriving early, and arriving late.
B.The trials are independent.
C.The experiment is performed until a desired number of successes is reached.
D.The probability of success is the same for each trial of the experiment.
E.There are two mutually exclusive outcomes, success or failure.
F.The experiment is performed a fixed number of times.
G.Each trial depends on the previous trial.
(b) The probability that exactly 17 flights are on time is
(Round to four decimal places as needed.)
Interpret the probability.
In 100 trials of this experiment, it is expected about _ to result in exactly 17 flights being on time.
(Round to the nearest whole number as needed.)
(c) The probability that fewer than 17 flights are on time is _
(Round to four decimal places as needed.)
Interpret the probability.
In 100 trials of this experiment, it is expected about _ to result in fewer than 17 flights being on time.
(Round to the nearest whole number as needed.)
(d) The probability that at least 17 flights are on time is _
(Round to four decimal places as needed.)
Interpret the probability.
In 100 trials of this experiment, it is expected about _ to result in at least 17 flights being on time.
(Round to the nearest whole number as needed.)
(e) The probability that between 15 and 17 flights, inclusive, are on time is _
(Round to four decimal places as needed.)
Interpret the probability.
In 100 trials of this experiment, it is expected about _ to result in between 15 and 17 flights, inclusive, being on time.
In: Statistics and Probability
Mr. Jackson could think about his experiment a little differently. How many times should he expect to roll a 4 if he rolls his number cube 30 times? This is called the mean, or expected value. You can find it if you know the number of trials and the probability of success for an individual trial. Use the formula μx = np to find the expected value.
Part A: Find the expected value for the number of times you would roll a 4 in 30 rolls of a number cube.
a. How many trials, n, are there?
b. What is p, the probability of success for each trial?
c. What is the expected value of rolling a 4 in 30 rolls of a number cube?
Part B: You can also find the standard deviation for the binomial probability distribution of a specific outcome in a binomial experiment. Use the formula to find the standard deviation. You've already identified n and p in Part A. Show your work, and round your answer to two decimal places.
Part C: You've seen that a cumulative binomial probability is
the probability of getting a number of successes within a given
range. It's easiest to use your calculator's binomcdf command to
find these. Find each of the probabilities described below. Show
your work, and round your answer to three
decimal places.
a. What is the probability that Mr. Jackson will roll a 4 at
most 5 times out of his 30 rolls of a
number cube?
b. What is the probability that Mr. Jackson will roll a 4 at least 5 times out of his 30 rolls of a number cube?
c. What is the probability that Mr. Jackson will roll a 4 between 3 and 7 times, inclusive, out of his 30 rolls of a number cube? Use this formula: P(a ≤ x ≤ b) = binomcdf(n,p,b) – binomcdf(n,p,a – 1).
In: Statistics and Probability
1. Two cards are drawn from a well-shuffled ordinary
deck of 52 cards. Find the probability that they are both aces if
the first card is (a) replaced, (b) not replaced.
2. Find the probability of a 4 turning up at least once in two
tosses of a fair die.
3. One bag contains 4 white balls and 2 black balls; another
contains 3 white balls and 5 black balls. If one ball is drawn from
each bag, find the probability that (a) both are white, (b) both
are black,(c) one is white and one is black.
4. Box I contains 3 red and 2 blue marbles while Box II contains 2
red and 8 blue marbles. A fair coin is tossed. If the coin turns up
heads, a marble is chosen from Box I; if it turns up tails, a
marble is chosen from Box II. Find the probability that a red
marble is chosen.
5. A committee of 3 members is to be formed consisting of one
representative each from labor, management, and the public. If
there are 3 possible representatives from labor,2 from management,
and 4 from the public, determine how many different committees can
be formed
6. In how many ways can 5 differently colored marbles be arranged
in a row?
7. In how many ways can 10 people be seated on a bench if only 4
seats are available?
8. It is required to seat 5 men and 4 women in a row so that the
women occupy the even places. How many such arrangements are
possible?
9. How many 4-digit numbers can be formed with the 10 digits
0,1,2,3,. . . ,9 if (a) repetitions are allowed, (b) repetitions
are not allowed, (c) the last digit must be zero and repetitions
are not allowed?
10. Four different mathematics books, six different physics books,
and two different chemistry books are to be arranged on a shelf.
How many different arrangements are possible if (a) the books in
each particular subject must all stand together, (b) only the
mathematics books must stand together?
11. Five red marbles, two white marbles, and three blue marbles are
arranged in a row. If all the marbles of the same color are not
distinguishable from each other, how many different arrangements
are possible?
12. In how many ways can 7 people be seated at a round table if (a)
they can sit anywhere,(b) 2 particular people must not sit next to
each other?
13. In how many ways can 10 objects be split into two groups
containing 4 and 6 objects, respectively?
14. In how many ways can a committee of 5 people be chosen out of 9
people?
15. Out of 5 mathematicians and 7 physicists, a committee
consisting of 2 mathematicians and 3 physicists is to be formed. In
how many ways can this be done if (a) any mathematician and any
physicist can be included, (b) one particular physicist must be on
the committee, (c) two particular mathematicians cannot be on the
committee?
16. How many different salads can be made from lettuce, escarole,
endive, watercress, and chicory?
17. From 7 consonants and 5 vowels,how many words can be formed
consisting of 4 different consonants and 3 different vowels? The
words need not have meaning.
18. In the game of poker5 cards are drawn from a pack of 52
well-shuffled cards. Find the probability that (a) 4 are aces, (b)
4 are aces and 1 is a king, (c) 3 are tens and 2 are jacks, (d) a
nine, ten, jack, queen, king are obtained in any order, (e) 3 are
of any one suit and 2 are of another, (f) at least 1 ace is
obtained.
19. Determine the probability of three 6s in 5 tosses of a fair
die.
20. A shelf has 6 mathematics books and 4 physics books. Find the
probability that 3 particular mathematics books will be
together.
21. A and B play 12 games of chess of which 6 are won by A,4 are
won by B,and 2 end in a draw. They agree to play a tournament
consisting of 3 games. Find the probability that (a) A wins all 3
games, (b) 2 games end in a draw, (c) A and B win alternately, (d)
B wins at least 1 game.
22. A and B play a game in which they alternately toss a pair of
dice. The one who is first to get a total of 7 wins the game. Find
the probability that (a) the one who tosses first will win the
game, (b) the one who tosses second will win the game.
23. A machine produces a total of 12,000 bolts a day, which are on
the average 3% defective. Find the probability that out of 600
bolts chosen at random, 12 will be defective.
24. The probabilities that a husband and wife will be alive 20
years from now are given by 0.8 and 0.9, respectively. Find the
probability that in 20 years (a) both, (b) neither, (c) at least
one, will be alive.
ok, I'll update this to 3 to 4 questions. Thanks!
In: Statistics and Probability
The University of Miami bookstore stocks textbooks in preparation for sales each semester. It normally relies on departmental forecasts and preregistration records to determine how many copies of a text are needed. Preregistration shows 95 operations management students enrolled, but bookstore manager Vaidy Jayaraman has second thoughts, based on his intuition and some historical evidence. Vaidy believes that the distribution of sales may range from 75 to 95 units, according to the following probability model:
Demand | 75 | 80 | 85 | 90 | 95 |
Probability | 0.05 | 0.20 | 0.20 | 0.20 | 0.35 |
This textbook costs the bookstore $82 and sells for $107. Any unsold copies can be returned to the publisher, less a restocking fee and shipping, for a net refund of $36.
a) Based on the given information, Vaidy's conditional profits table for the bookstore is:
| Demand | |||||
| 75 | 80 | 85 | 90 | 95 | |
| Stock | p=0.05 | p=0.20 | p=0.20 | p=0.20 | p=0.35 |
| 75 | 1875 | 1875 | 1875 | 1875 | 1875 |
| 80 | 1645 | 2000 | 2000 | 2000 | 2000 |
| 85 | 1415 | 1770 | 2125 | 2125 | 2125 |
| 90 | |||||
| 95 |
b) How many copies should the bookstore stock to achieve highest expected value?
c) The EMV of stocking this number of copies is
In: Operations Management
. (1) A man has a 4-sided (tetrahedral) die, with four faces, 1, 2, 3, and 4. He rolls it 12 times. (a) Given that for each roll of the die, the probability of rolling a 4 is 1/4 and the probability of not doing so is 3/4, compute the following probabilities P(x = x0),where x is the number of times that the man rolls a 4 among the 12 trials. (b) What is the average value of x? What is the standard deviation? (c) Which possible value of x has the highest likelihood of occurring? (2) IQ scores in America, by definition, are normally distributed, with 100 points being the mean IQ and the standard deviation being 10 points. (a) Suppose a person has an IQ of 115. What percentage of the population is expected to have a higher IQ than this person? (b) Now suppose a person has an IQ of 75. What percentage of the population is expected to have a lower IQ than this person? (c) An individual’s IQ was claimed to have jumped from 83 to 212 after a procedure. (An IQ of 212 is not possible, given that most tests only can assign scores of at most 170.) What percentage of the population, were the claim not false, would be between the first score and the second?
In: Statistics and Probability
Player I and player II each have two pennies. Each player holds 0, 1, or 2 pennies in his left hand and the remainder of the pennies (2, 1, or 0 respectively) in his right hand. Each player reveals both hands simultaneously. If the number of coins in one of player I's hands is greater than the number of coins in the respective hand of player II, player I wins the difference in pennies; otherwise, no money is exchanged.
(a). Find the von Neumann value and the optimal strategy for each player in the game. If any player has infinitely many optimal strategies, find all optimal strategies.
(b). If player I owed $100 to player II, approximately how many rounds of the game would have to be played, on the average, to cancel the debt?
In: Statistics and Probability
Suppose you are deciding how to invest $2,000. There are
two
options: shares in an airline company and shares in a petroleum
company. There is a 0.25
probability that oil prices will go up, a 0.25 probability that
prices will go down, and a 0.50
percent probability they will remain the same. The value of each
$100 invested after prices
adjust is as follows:
| Event | Probability | Airline | Oil Company |
| prices fall | 0.25 | $120 | $70 |
| prices same | 0.50 | $105 | $110 |
| prices rise | 0.25 | $80 | $130 |
a. Calculate the expected value and standard deviation of the value
of the total investment if
you invest the entire $2,000 in the airline company.
b. Calculate the expected value and standard deviation of the total
investment if you invest
the entire $2,000 in the oil company.
c. Calculate the expected value and standard deviation of the total
investment if you invest
$1,000 in the airline and $1,000 in the oil company.
d. Which investment (‘a’, ‘b’, or ‘c’) has the highest risk? Which
has the lowest risk?
In: Economics
A company has a total of 30 employees.
17 employeers graduated from Berkeley.
Out of 30 employees, 18 are native Californians. Furthermore,
the company has 12 mechanical
engineers. Still, only 1 employee can claim the highest honor of
being a native Californian, Berkely graduate mechanical
engineer.
(a)If an employee is selected at random from this company, what
is the probability
that this employee is a Berkely graduate?
(b)A survey reveals that, out of 12 mechanical engineering
working at this company,
half are native Californians. How many Californians are not
mechanical engineers?
(c)Suppose that a native Californian is selected at random. The
probability that this
employee is an Berkeley graduate is 1/2. If a Berkeley graduate is
chosen at random, what is the probability that this employee is a
native Californian?
(d)When the Berkeley graduates come together for a basketball
game, there are only 3
mechanical engineers in the room. If an employee is selected at
random from this company,
what is the probability that this employee is an mechanical
engineer but neither a Berkeley graduate
nor a native Californian?
Please show work
In: Statistics and Probability
QUESTION 1
Studd Enterprises sells big-screen televisions. A concern of management is the number of televisions sold each day. A recent study revealed the number of days that a given number of televisions were sold.
# of TV units sold # of days
0 2
Answer the questions below. For each part, show your calculations and/or explain briefly how you arrived at your answer, as appropriate or needed.
Required:
In: Statistics and Probability