|
Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 59691: please i need your help
cast adie anumber of independent times until six appears on the up side of the die
1. find the pdf of x, the number of casts needed to obtain that first six,
2. show that the summation from 1 to inf for f(x)=1
3. determine p(x=1,3,5,7....)
3. find the distribution function F(x) =p(X
Click here to see answer by stanbon(26259)   |
Question 58616: 9 houses are built on a circular road. Each house is painted red, white, or blue with a probability 1/3 for each color. What is the probability that no two adjacent houses are the same color.
Is this simply 2/3 since the probability of any adjacent house not being the same color is 2 out of 3??? Seems too simple.
Click here to see answer by stanbon(26259) |
Question 54244: Hi,
I desperately need help with a probability and statistics problems.
Q) How many paths can a rook move from the lower left corner of a chessboard to the diagonally opposite corner by moving only up or the right at each step?
Here is what I have for the answer, but not sure:
(2n ) or (14 )
( n ) ( 7 )
Thank you very much for those like to help.
Click here to see answer by stanbon(26259) |
Question 63585This question is from textbook Algebra and Trigonometry Structure and Method
: Hell, I'm Alex. Could I please ask your assistance on these two Homeschool American School Problems because I don't have a teacher here to help?
What is the (a)variance and the (b) standard deviation of the following scores:
51, 55, 61, 62, 68, 71, 71,73, 81, 82, 87, 89, 92, 94, 95, 100
Thank you! :]This question is from textbook Algebra and Trigonometry Structure and Method
Click here to see answer by stanbon(26259) |
Question 63779: Kindly assist.
A game of chance consist of tossing 3 coins one . For every head that shows up one gain $ 300 and $ losses $ 200 for each tail that appears .
a) Determine the expected value of the game
b) Dtermin the Standard deviation of the game
c) It is prudent for one to play the game ?
Click here to see answer by stanbon(26259) |
Question 64118: I am a man who was out to sea from the 4th or March to the 24th of April. My wife had a baby that was born on the 20th of December what are the chances that the baby is mine. I have information from a credible source that states that a healthy female is normally distributed with a mean of 268.2 days and a standard deviation of 15.1 days.
Click here to see answer by stanbon(26259) |
Question 51699: A small town has 5,600 residents. The residents in the town were asked whether or not they favored building a new bridge across the river. You are given the following information on the residents' responses, broken down by sex.
Men Women Total
In Favor 1,400 280 1,680
Opposed 840 3,080 3,920
Total 2,240 3,360 5,600
Let: M be the event a resident is a man
W be the event a resident is a woman
F be the event a resident is in favor
P be the event a resident is opposed
a. Find the joint probability table.
b. Find the marginal probabilities.
c. What is the probability that a randomly selected resident is a man and is in favor of building the bridge?
d. What is the probability that a randomly selected resident is a man?
e. What is the probability that a randomly selected resident is in favor of building the bridge?
f. What is the probability that a randomly selected resident is a man or in favor of building the bridge?
g. A randomly selected resident turns out to be male. Compute the probability that he is in favor of building the bridge.
Click here to see answer by stanbon(26259) |
Question 47178: 1)Find the probability of selecting both red cards when two cards are drawn (without replacement) from a standard deck of cards
2)Find the probability of drawing a heart or a club from a standard deck of cards.
3)Find the probability of getting a three first and then a four when the die is rolled twice.
Click here to see answer by stanbon(26259) |
Question 64374: A researcher wants to determine whether or not the percentage in population A is less than the percentage in population B. A sample of 161 items from population A had a sample percentage of 20% while a sample of 189 items from population B had a sample percentage of 25%. If a significance level of .05 is used, which of the following statements is correct?
1. left-tailed test with Z = -1.96
2. left-tailed test with Z = -1.65
3. left-tailed test with Z = +1.65
4. right-tailed test with Z = +1.65
5. left-tailed test with Z = -2.33
I figured t-score=1.113, degrees of freedom=348, its a two-tailed test=.2665, from here I am lost. can someone help me please....
Click here to see answer by stanbon(26259) |
Question 64373: 2 psychologists, Alfred and Bertha, have theories about schizophrenia in the American population. Alfred claims that 20% of Americans suffer from schizophrenia. Bertha disagrees, but is unsure whether the percentage is higher or lower. Bertha sampled 400 people randomly, and found 103 actually had schizophrenia. If she set a significance level of .05, which of the following is appropriate?
1.Ho: p=.20
2.Ho: p is not= .20
3.Ha: p= .20
4.Ho: p>.20
5.none of these
What I know: n=400, p=.2,
from there I am stumped, please help me... thank you very much.....
Click here to see answer by stanbon(26259) |
Question 46432: Hi there,
This question is an ANOVA so it's very long. Could someone please help me with it. I would be so grateful to you.
Assume that the wages are normally distributed
This should be in a chart. The top and bottom numbers correspond with each other. For example, 48.6 and 57.6 are in a square together. 48.6 is above 57.6.
Montreal
48.6 61.9 19.8 35.2 25.5 58.4 47.4 48.6 17.6
57.6 81.1 26.1 76.8
Toronto
32.9 46.4 19.7 24.0 19.7 18.4 25.2 10.3 26.9
20.5 52.6 40.7 24.4 36.5 33.9 28.0 35.3 25.5
Vancouver
22.7 36.0 20.7 26.8 24.0 49.2 29.5 28.8 38.8
35.8 23.1 27.6 30.8 33.5 23.3 38.7
a. At ά=0.05, is there enough evidence to conclude that the variance in annual wages differ for Montreal to Toronto?
Provide hypothesis, variance, p and critical values and conclusion
b. Are the mean annual wages equal fro all three cities at ά=0.10
Provide hypothesis, variance, p and critical values and conclusion.
Thanks for your help,
Please Please Please help me.
Thanks a lot,
Shelly
Click here to see answer by stanbon(26259) |
Question 64393: Mr. Meyers used 2 different teaching methods in similiar statistics classes of 35 students each. Then each class took the same practice exam. in one class there was a mena grade of m=82 and s=4; in the other the m=77 and s=7. Mr Meyers wants to be 95% certain of any conclusions drawn from the data.
a. assume Ho: the mean grade is the same for both teaching methods. What should the alternative hypothesis be?
b. Is the distribution of differences approximately normal? Why or Why not?
c. Should Mr. Meyers reject or fail the null hypothesis? Draw a diagram that supports your answer.
for a. I put Ho:m=m
b. I said yes the distribution of differences is normal.
I drew a diagram but I believe I have it labeled incorrectly.
Click here to see answer by stanbon(26259) |
Question 64395: A student has a coin that she claims is biased towards heads. She believes that it will result in heads 60% of the time. She finally decides to test the coin and see if her claim is true, before she takes it to Las Vegas to make her fortune. She flips the coin 30 times, keeping track of S, the number of times it comes up heads. Assuming Ho: p=0, Ha: p>.6, calculate the following, show your work.
a. Theoretical mean for the distribution of S.
b. Theoretical standard deviation of distribution of S
c. The number of heads (S) necessary to reject Ho at the .05 significance level.
m=0,standard deviation= 7.2, S=
this is as far as I got am I on the right track?
Click here to see answer by stanbon(26259) |
Question 64403: A total of 15 children who had flouride treatment were compared with 15 who did not. Of those who used flouride, the mean number of cavities m was .8 with s=.07. For those who did not use flouride, m was 1.4 with s=.09. Test the hypothesis that there is no difference between these two groups of children at the .05 significance level, and show all work supporting your conclusion and the method you use.
Click here to see answer by stanbon(26259) |
Question 64429: A random sample of 1000 students showed 535 perfer coffee over tea. If the percentage of students who prefer coffee is p, test Ho: p =.50 versus Ha: p>.50 at the .05 significance level. My conclusion should be:
1. reject Ho and conclude the evidence supports Ha
2. fail to reject Ho
3. gather more data because I am unable to complete the analysis as stated
4. inclusive of Student's (t) test because of the sample size
5. none of these answers
Click here to see answer by stanbon(26259) |
Question 64428: Assume Ho: p=.92 and Ha: p is not equal to .92. If the significance level is .05, and a random sample of 4000 observations includes 3600 sucessess, what decision should be made?
1. Accept Ho
2. Reject Ho
3. Reject Ha
4. Resample; the sample size is too large
5. None of these
Click here to see answer by stanbon(26259) |
Question 64456: Evaluate:
8
(4x2 + 9x - 11) dx
3
(2 decimal places)
______________________________________________________________________________
Find the specific antiderivative, f(x), of the function below with the given initial condition. f'(x) = 3x2 - 6x + 5, f(0) = 3.
_______________________________________________________________________________
Evaluate:
8
(5x2 - 14x - 4) dx
3
(2 decimal places)
_______________________________________________________________________________
The marginal cost function for producing x units of a certain product is given by:
C'(x) = 8 + 0.05x
Find the total cost incurred by increasing the production level from 100 to 700 units. (2 decimal places)
_______________________________________________________________________________
Evaluate:
8
(4x2 - 10x + 43) dx
-4
(2 decimal places)
_______________________________________________________________________________
Find the average value of the function
f(x) = 4x3 - 6x over the interval [0,9].
Click here to see answer by stanbon(26259) |
Question 64573: The question "Do more than 40% of cat owners own dogs?" leads to a two tailed test. T or F
Under a one tailed test with the level of significance set at .05 the probability of erroneously rejecting a true hypothesis is .05. T or F
Click here to see answer by stanbon(26259) |
Question 64638: An investor holds shares i three independents companies, companies A, B and C. An analyst predicts the probability of profit increases for each company as follows:
Company A: 0.70
Company B: 0.50
Company C: 0.65
1. If the analyst's predictions are correct, what is the probability that all 3 companies show a profit increase? (express your answer to the nearest hundredth of one percent)
2. If the analyst's predictions are true, what is the probability that at least one company shows a profit increase?(express your answer to the nearest hundredth of one percent)
Click here to see answer by stanbon(26259) |
Question 23891: Cody has had problems starting his two cars during the winter months. He decided to record the number of times each car starts during one month period this winter. He attempted to start each car every morning for 30 days. He recorded the following information:
-His first car started 20 times
-His second car started 18 times
-Both cars started 40% of the time
What is the probability that on any particular morning during the month:
a) at least one of the cars start?
b) he cannot start either of his two cars?
Click here to see answer by stanbon(26259) |
Question 23888: Kathleen, Angela, and Lisa are the only entrants in a competition for which there is a prize for first place and a prize for second place. Consider the experiment of selecting the first and second place winners.
Of the following events:
P-Kathleen wins first prize
Q-Kathleen wins second prize
R-Kathleen wins a prize
S-Angela and Lisa win the prizes
a) Which of these events are mutually exclusive?
b) List all pairs of these events that are mutually exclusive
Click here to see answer by stanbon(26259) |
Question 64811This question is from textbook A survey of mathematics
: This is my last question I promise, I think I finally may have this.
A pet shop is selling a calico cat, a Siamese, persian, and a Himalayan cat. The Chens are going to select two cats to bring home as pets.
a. determine the number of points in the sample space.
b. construct a tree diagram and list the sample space
c. find the probaility that they will select the Persian cat, the Persian cat and the Calico,cats other than the Persian CatThis question is from textbook A survey of mathematics
Click here to see answer by stanbon(26259) |
|
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
|
| |
