Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 450570: For Adam the probability a bull's eye with a bow and arrow is .4.
Adam will take 5 shots.
a) What type of probability distribution is this?
b) Complete the chart to show the probability distribution for the random variable X which represents the number of possible bull's eyes its associated probability.
X = # Bull's Eyes P(X)
c) What is the probability that Adam will get at least 2 bull's eyes?
d) How many bull's eyes do you expect him to make?
____________
A box contains 5 dozen heads of lettuce. There are eight spoiled heads in the box. A person chooses a dozen heads at random.
a) What is the expected number of spoiled heads that will be chosen?
b) What is the probability that he did not choose any of the spoiled heads?
Click here to see answer by edjones(7569)  |
Question 450664: Let be a standard normal random variable. Calculate the following probabilities using the calculator provided. Round your responses to at least three decimal places. P(Z>-1.99)=
P(Z [LESS THAN OR EQUAL TO]< 0.57)=
P(-1.39< Z < 2.04)=
Click here to see answer by stanbon(57361) |
Question 450904: Hi everyone, I'm having problems trying to work out the solutions to these two questions, is there someone out there who can please help me understand it?? Thankyou heaps
The probability that a flavoured milk container holds more than 500mL of use is 0.2. If a batch of 10 of these milk containers is tested, what is the probability that:
(a) At least half of them will contain more than 500mL?
(b) None of them will contain more than 500mL?
Amy thinks that all brands of chocolate taste the same. She decides to test four brands by having 20 people test them and state their preference. Her results are shown below.
Brand of Chocolate
Cadbury - 8
Nestle - 4
Hersheys - 5
Pams - 3
(a) Copy and complete the table to show the expected frequencies in this problem.
(b) Perform the x2 test to see whether there appears to be any significant preference for one brand of chocolate over another.
Click here to see answer by stanbon(57361) |
Question 451045: The number of dry cleaning orders picked up at Sunny Fresh Dry Cleaners was sampled over 12 hour periods. Below is the sample:
142 171 125 91 140 125 97 125 162 142
125 117 89 125 140 128
From this data set, compute the sample mean, median, mode and midrange. Compute the 1st
quartile and 3rd and interpret their meanings.
this is what I have so far and I am stuck
142+171+125+91+140+125+97+125+162+142+125+117+89+125+140+128/16
19361/16
120.6875
91,97,125,125,125,125,125,128,140,140,142,142,162,171,206
middle term/median 128
mode
125 occurs 5 times
97,125,125,125,125,125,128,140,140,142,142,162,171,206
206-91=115
125+125= 250 1st Q 250/3= 83.33
171+206=377 3rd Q 377/2 =
Click here to see answer by edjones(7569)  |
Question 451067: Having problems understanding Random Variable, Probability Distribution and Expected Value. Please help.
Question 1. The annual premium for a $5000 insurance policy against the theft of a painting is $150. If the (empirical) probability that the painting will be stolen during the year is.01, what is your expected return from the insurance company if you take out this insurance?
Question 2. On three rolls of a single die, you will lose $10 if a 5 turns up at least once, and you will win $7 otherwise. What is the expected value of the game?
Click here to see answer by stanbon(57361) |
Question 451066: An ordinary fair die is a cube with numbers 1 through 6. The die is rolled twice in succession, and the face value of the two rolls are added together. This sum is recorded as the outcome of a single trial of a random experiment. Compute the probability of the following events:
Event A: The sum is greater than 7.
Event B: The sum is divisible by 5 or 6 (or both).
(Please write answers as exact fractions.) Thank you!
Click here to see answer by stanbon(57361) |
Question 451195: I have a multiple choice question that asks about the rejection areas. I've been trying to solve since Monday and still do not "get it"..
What are the two rejection areas in using a two-tailed test and the 0.01 level of significance?
A. Above 1.96 and below –1.96
B. Above 1.65 and below –1.65
C. Above 2.58 and below –2.58
D. Above 1.00 and below –1.00
E. None of the above
Click here to see answer by ewatrrr(10682)  |
Question 451226: Given U = {22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32}, A = {22, 24, 26, 28, 30}, and B = {23, 24, 25, 28, 29}.
Find A′U B′. finding A’, then B’ then find their union.
Click here to see answer by jim_thompson5910(28595) |
Question 451231: I have a multiple choice question that I've been working on with Megastat but I don't seem to be using megastat correctly.
Suppose a one-tailed t-test is being applied to find out if the population mean is less than $212. The level of significance selected is 0.01 and 26 accounts are sampled. What is the critical value?
A. –2.580
B. –2.485
C. –1.960
D. –2.479
E. None of the above
Any help will be greatly appreciated!
Click here to see answer by stanbon(57361) |
Question 451231: I have a multiple choice question that I've been working on with Megastat but I don't seem to be using megastat correctly.
Suppose a one-tailed t-test is being applied to find out if the population mean is less than $212. The level of significance selected is 0.01 and 26 accounts are sampled. What is the critical value?
A. –2.580
B. –2.485
C. –1.960
D. –2.479
E. None of the above
Any help will be greatly appreciated!
Click here to see answer by ewatrrr(10682)  |
Question 451341: In this carnival game project(that we have to do for math end of the year project), round 1 goes like this. Out of a deck of cards, you pull a card. If that card is a queen of hearts, you automatically win. If that card is a queen, or a heart(but a king of hearts will make you lose), you must go to the next round. Any other card(or a king of hearts), and you lose. I figured the probability of winning, losing, and moving to round two, on this to be 1/52 winning, 37/52 losing, and 14/52 moving to round two.
In round two, there are 10 cups(3 blue, 4 red, 3 clear). Players must bounce a ball. If the ball lands in a blue cup, they win. If the ball lands in a red cup, they lose. If the ball lands in a clear cup, they must move to round three. I figured the probability of winning round two to be 3/10, the probability of losing round two to be 4/10, and the probability of moving to round 3 to be 3/10.
In round three, players must pick a card from a deck of cards. If that card is a queen of hearts, they win. Any other card, and they lose. The probability of winning round 3 is 1/52, and the probability of losing round 3 is 51/52.
My question is this: What is the probability of winning the whole game?
Click here to see answer by stanbon(57361) |
Question 451339: 3. (3 points) Using the 5-step hypothesis testing model test to see if average income of a group is greater than 35,000. Assume ratio level data. Use an alpha of 5%. When data is collected the sample mean is 36,500. The population standard deviation is known to be 5,000 (so a z test can be used).
Click here to see answer by stanbon(57361) |
Question 451410: Late payment of medical claims can add to the cost of health care. The auditing firm of Dewey, Cheatham, and Howe has discovered that for one insurance company, 85.1% of the claims were paid in full when first submitted based on a sample of 200 claims. Suppose that the insurance company developed a new payment system in an effort to increase this percentage. A sample of 200 claims processed under this new system revealed that 180 of the claims were paid in full when first submitted. At the 5% level of significance, is there evidence that the population proportion of claims paid in full under this new system is higher than the proportion of claims paid in full under the old system?
Q-2a: State the null hypothesis
Q-2b: State the alternative hypothesis.
Q-2c: Perform the hypothesis test and state your conclusions and evidence.
Click here to see answer by stanbon(57361) |
Question 451336: 2. (3 points) Set up the null and alternate hypotheses for the situations where the analyst is trying to prove
a. The average income of men is greater than that of the average income of women
b. The average age of the workforce is greater than 30 years
c. A new car model will get greater average gas mileage than the old model
Click here to see answer by stanbon(57361) |
Question 451288: I have a multiple choice question that I believe the answer is "E. None of the above" because my answer i keep getting doesn't match. I posted the question and the possible answers that it could be. Any help with this is greatly appreiated....
The net weights of a sample of bottles filled by a machine manufactured by Edne, and the net weights of a sample filled by a similar machine manufactured by Orno, Inc., are (in grams): Edne: 5, 8, 7, 6, 9 and 7 Orno: 8, 10, 7, 11, 9, 12, 14 and 9 Testing the claim at the 0.05 level the mean weight of the bottles filled by the Orno machine is greater than the mean weight of the bottles filled by the Edne machine, what is the critical value?
A. –1.96
B. –2.837
C. –6.271
D. +3.674
E. None of the above
Click here to see answer by stanbon(57361) |
Question 451476: You want to estimate the mean repair cost for dishwashers. The estimate must be within $10 of the population mean. Determine the required sample size to construct 99% confidence interval for the population mean. Assume the population standard deviation is $22.50.
Click here to see answer by stanbon(57361) |
Question 451261: What is the sample size needed to be able to estimate the mean dollars that each card holder will spend each month. It would like to be within plus or minus $25 of the true mean with a 98% confidence level. It would like to be within plus or minus $25 of the true mean with a 98% confidence level. The standard deviation is thought to be $400. How many card holders should be sampled?
Click here to see answer by stanbon(57361) |
Question 451536: SAT I scores around the nation tend to have a mean scale score around 500, a standard deviation of about 100 points and are approximately normally distributed. A person who scores 700 on the SAT I has approximately what percentile rank within the population?
Can you show me step-by-step how to do this?
Thank you
Click here to see answer by ewatrrr(10682)  |
Question 451683: A computer manufacturer is about to unveil a new, faster personal computer. The new machine clearly is faster, but initial tests indicate there is more variation in the processing time. The processing time depends on the particular program being run, the amount of input data, and the amount of output. A sample of 16 computer runs, covering a range of production jobs, showed that the standard deviation of the processing time was 22 (hundredths of a second) for the new machine and 12 (hundredths of a second) for the current machine. At the .05 significance level can we conclude that there is more variation in the processing time of the new machine?
Click here to see answer by stanbon(57361) |
Question 451646: The movie rating Web site Rotten Tomatoes reported that 92 percent of a sample of 39 movie critics hated the 2005 horror movie The Fog. If you asked all the movie critics in the country what they thought of this movie, what is the best estimate of the percentage that would hate it?
Click here to see answer by stanbon(57361) |
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