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Tutors Answer Your Questions about Probability-and-statistics (FREE)
Question 80435: During the hunting season Ken arms himself with his bow and arrows(30% of the time) or his rifle(70% of the time).
If Ken uses his archery skills to bag his game the probabilities of success are: turkey=60%, deer=80%, and bear 30%
However if he uses his rifle, his success probabilities rise to: turkey=80%, deer 90%, and bear 60%
What is the probability of Ken making a triple kill this hunting season?
a. 0.0432
b. 0.3024
c. 0.3456
d. 0.6544
e. none of the above
Click here to see answer by Edwin McCravy(2920)   |
Question 80681: I sent this one before but made some misstakes sorry. In the question u is for population mean and o is for Population standards deviation thank you .
Let X be a normally distributed random variable with u=100 and o=15 . The probability that is between 80 and 120 is (to the nearest whole percent)
a. 8 % b. 82 % c. 91% d. answer not listed
Click here to see answer by stanbon(26259) |
Question 80677: looking for another opinion on this question
What is the minimum percentage of data in any frequency distribution that lies within three standard deviations of its mean?
a. 67% b. 75%
c. 25% d. answer not listed.
I think it is b but not sure thank you for the help
Click here to see answer by rapaljer(3617) |
Question 80686: looking for some help and need it too. one question has me stoped dead and two others just want someone to check my work thank you.
Among 100 people randomly chosen in a survey, 10 stated that they believed that the elected representatives are honest most of the time. The approximate 95% confidence interval for the percentage of the population who believe that such people are honest most of the time is
For questions 11 and 12 use the table immediately below. The table shows the number of smokers and nonsmokers by gender among 210 randomly selected people.
Smokers Nonsmokers Totals
Male 30 60 90
Female 40 80 120
Totals 70 140 210
_____11. If a smoker is chosen at random, the probability that the person is male is
12. If a male is chosen at random, the probability that he is a smoker is
would like to get a nother look at 11 and 12 I think 11 is 30/70 and 12 is no answer with this data.
thank you for your time.
Click here to see answer by stanbon(26259) |
Question 80839: One card is selected from a deck of standard poker cards at random. Assume a typical deck of 52 totals cards numbered from 2 thru 10 and Jack thru Ace, such that there are 13 red hearts, 13 red diamonds, 13 black spades, and 13 black clubs. Find the probability the card is RED and LESS THAN 4 (that is, RED and 2 or 3 ONLY.
A. 1
B. 2/13
C. 1/13
D. 17/26
Click here to see answer by checkley75(3666) |
Question 80838: Assume there are 10 people taking this class. 3 recieve a grade of "A", 4 recieve a grade of "B" and 3 recieve a grade of "C". What are the odds that the next person to enter the class will recieve a grade of "B"?
A. 2:3
B. 3:2
C. 2:5
D. None of the above
Click here to see answer by checkley75(3666) |
Question 80842: Assume the following data set for points scored in a basketball game by a player Data Set: (12, 15, 20, 23, 29, 30). Assuming a standard normal distribution what would be the percentage of basketball games where the player should score more than 25 points?
A. 18.4%
B. 50%
C. 31.6%
D. 68.4%
Click here to see answer by stanbon(26259) |
Question 80846: not sure how to type this but here goes
Let a random sample be taken of size n = 100 from a population with known standard deviation of o = 20 . Suppose that the mean of the sample is X = 37 . The approximate 68% confidence interval for the mean, u , of the population from which the sample was drawn is
n = n
o = Population standard deviation
X = Sample mean
u = population mean
I need some help on this question and my key board is short some keys. I hope that you can help thank you mirna.
Click here to see answer by stanbon(26259) |
Question 80844: Looking for some help. this question is a smoker.
Among 100 people randomly chosen in a survey, 10 stated that they believed that the elected representatives are honest most of the time. The approximate 95% confidence interval for the percentage of the population who believe that such people are honest most of the time is
thank you for your time and help.
Click here to see answer by stanbon(26259) |
Question 80837: Assume there are 10 people taking this class. 3 recieve a grade of "A", 4 recieve a grade of "B" and 3 recieve a grade of "C". What is the empirical probability the next person to enter the class will recieve a grade of "A"?
A. 2/5
B. 3/11
C. 3:10
D. 3/10
Click here to see answer by stanbon(26259) |
Question 80942: looking for some help I need to type the question out because I an short some key on my key board.
Let a random sample be taken of size n=100 from a population with known standard deviation of o=20 . Suppose that the mean of the sample is X=37 . The approximate 68% confidence interval for the mean, u , of the population from which the sample was drawn is
n = n
o = population standard deviation
X = sample mean
u = population mean
thank you for you time and help.
Click here to see answer by stanbon(26259) |
Question 81009This question is from textbook A survey of mathematics with applications
: The table below shows the number of tests taken by 30 randomly selected college sophomores
Number of tests taken Number of students
0 12
1 8
2 2
3 3
4 or more 5
_________________________________________________
If a student is selected at random, find the probability
a) the student has taken exactly two tests
b) the student has taken at least two tests
c) the student has taken at most three tests
d) the student has taken 3 or fewer tests
e) the student has taken one or two tests.
This question is from textbook A survey of mathematics with applications
Click here to see answer by stanbon(26259) |
Question 81325: Please Help! This will be greatly appreciated. (Show Step by step solutions to these problems I got incorrect on my test)Thank You.
Question 1
A local bank says that the standard deviation for bank account balances is less than or equal to $2150.91. A random sample of size n=16 bank accounts reveals a standard deviation of s=$2129.61. Assume that the bank balances are normally distributed. Test the hypothesis that the standard deviation for bank accounts is less than or equal to $2150.91 at the a=0.05 significance level.
Question 2
The following represents the mean scores on the same set of 5 statistics exams given in Spring 2004 and Fall 2004. Test the claim that the mean scores for the Spring 2004 semester were not equal to the mean scores for Fall 2004 semester. Use a=0.05.
Spring 2004- Test 1= 48.7, Test 2= 68.9,Test 3= 75.2, Test 4= 94.3, Test 5= 98.7
Fall 2004- Test 1= 49.0, Test 2= 68.8, Test 3= 75.5, Test 4= 95.1, Test 5= 100.6
Question 3
An instructor wanted to test the effectiveness of a CALS (Computer Aided Learning System). Two classes were offered in Statistics I. One class used a CALS and the other used traditional methods. At the end of the two courses both classes were given the same final exam. The CALS class had 117 students and 19 of the class receives a grade of B or higher. The class taught using traditional methods had 143 students and 39 of the class receives a grade of B or higher. At a=0.05 can you conclude that the CALS produced a smaller proportion of students with a grade of B or higher.
Question 4
Test the claim that the difference between the mean salary for computer programmers and the mean salary for photographers in Wisconsin is not equal to 28,000. The results of a survey of randomly selected computer programmers and photographers in Wisconsin are shown in the figure below.
Use alpha= 0.01 and Rejection Region test. Testing a Difference other than zero.
Photographers and Computer Programmer Salaries
Computer programmers
x1= $52,400
s1= $8,290
n1= $31
Photographers
x2= $24,200
s2= $3,490
n2= $32
Click here to see answer by stanbon(26259) |
Question 81424: An electronic toy manufacturer uses a particular kind of quality test to check the toys. The test indicates defects in 85% of defective toys, but it also indicates defects in 2% of nondefective toys. The test indicates that toy A is defective. If 5% of toys have defects, what is the probability that toy A has a defect?
Click here to see answer by stanbon(26259) |
Question 82070: If Sally can paint a house in 4 hours and John can paint the same house in 6 hours, how long will it take to paint the same house together?
A. 2 hr. 24 min
B.3 hr. 12 min.
C. 3 hr. 44 min.
D. 4 hr. 10 min.
E. 4 hr. 33 min.
I tried to solve by dividing both of their times by 2 but that gave me 5 and it wasn't one of the answer choices. How would you solve this?
Click here to see answer by stanbon(26259) |
Question 82070: If Sally can paint a house in 4 hours and John can paint the same house in 6 hours, how long will it take to paint the same house together?
A. 2 hr. 24 min
B.3 hr. 12 min.
C. 3 hr. 44 min.
D. 4 hr. 10 min.
E. 4 hr. 33 min.
I tried to solve by dividing both of their times by 2 but that gave me 5 and it wasn't one of the answer choices. How would you solve this?
Click here to see answer by dolphinlover100(1) |
Question 82413: In order for a fast food restaurant to recieve asuperior rating, the kitchen staff must recieve a rating of at least 4 ona scale of 1 to 5 and the counter crew a rating of 5 on a scale of 1 to 5. the probablity of a kitchen crew recieving a score of 4 or better in any given restuarant is 87%. the probability of a counter crew receiving a rating of 5 is 75% for any given restaurant.
Find the probability that a restaurant receives a superior rating?
Find the probability that a restaurant will not receive high enough scores in either category?
Find the probability that a restaurant will not receive a superior rating.
Click here to see answer by stanbon(26259) |
Question 82936: Can someone show me step by step the correct answer. Thanyou It will be greatly appreciated.
Question 1
The following represents the mean scores on the same set of 5 statistics exams given in Spring 2004 and Fall 2004. Test the claim that the mean scores for the Spring 2004 semester were greater than or equal to the mean scores for the Fall 2004 semester. Use a= 0.10
Spring 2004
Test 1 =46.0, Test 2= 47.1, Test 3= 55.7, Test 4= 58.2, Test 5= 62.4
Fall 2004
Test 1= 46.3, Test 2= 47.2, Test 3= 55.2, Test 4= 57.6, Test 5=63.6
Click here to see answer by stanbon(26259) |
Question 83092: Data Set #1
44, 35, 44, 22, 40, 40, 72, 21, 72, 70
Data Set #2
7.8, 4.9, 4.9, 3.8, 4.4, 7.1, 3.3, 7.6, 4.0, 3.1, 6.0
Find Mean, Median, Mode, Sum of squares, Variance, Standard Deviation,
Of Data Set #1 and Data Set #2.
Click here to see answer by Mona27(45) |
Question 83387: USE THE DIE AND SPINNER. IF THE RESULTS OF A SECOND INDEPENDENT EVENT DO NOT DEPEND ON THE RESULTS OF THE FIRST ,TWO EVENTS CAN OCCUR AT THE SAME TIME AND ARE CALLED INDEPENDENT EVENTS. TO FIND THE PROBABILTY OF TWO INDEPENDENTEVENTS, MULTIPLY THE PROBABILITS OF EACH EVENTP(A AND B) =P(A)X P(B). P(6AND GREEN MULTIPY1/6AND 2/5 TOGETHER THEN REDUCE THE FRACTION IF POSSIBLE .i don't no how to multiply these fractions please help me .thanks
Click here to see answer by Mona27(45) |
Question 83419: the following table lists how poerty level income cutoffs (in dollars) for a family of four have changed over time
year/income
1970/3968
1975/5500
1980/8414
1985/10989
1990/13359
1995/15569
2000/17603
Let x be the year, with x = 0 corresponding to 1970, and y be the income in thousands of dollars. (note: symbol weird E x = 105, Weird Ex^2 = 2275, weird Ey=75.402, Weird Ey^2 = 968.270792, wierd Exy = 1460.97)
A) PLOT THE DATA. DO THE DATA APPEAR TO LIE ALONG A SRAIGHT LINE?
B) CALCULATE TH ECOEFFICIENT OF CORRELATION. dOES YOUR RESULT AGREE WITH YOUR ANSWER IN PART a?
C)fIND THE EQUATION OF THE LEAST SQUARE LINE.
d) uSE YOUR ANSWER FROM PART c TO PREDICT THE POVERTY LEVEL IN THE YEAR 2015.
Click here to see answer by stanbon(26259) |
Question 83418: Decrease in Banks The number of banks in the United
States has dropped about 30% since 1992. The following
data are from a survey in which x represents the years
since 1900 and y corresponded to the number of banks, in
thousands, in the United States.†
n=10 the weird E symbol x^2 = 93,205
werid E x = 965 weird E xy = 9165.10
weird y = 95.3 weird y^2 = 920.47
a. Find an equation of the least squares line.
b. If the trend continues, how many banks will there be in
2004?
c. Find and interpret the coefficient of correlation.
Click here to see answer by stanbon(26259) |
Question 83253: I'm having a really hard time understanding how to fill in this chart with so little to go on.
Produce a Cross Tabulation Table Self-Esteem by Gender
Break Self-Esteem into the following classes;
Low = a score less than 55;
Moderate a score between 55 to 75;
and High a score greater than 75.
Label your table.
Gender of Respondent
Self Esteem Male Female Total
Low Total 7
Moderate total 9
High total 4
Total total 20
Research Data (20 of 300)
What do the letters at the top of each of these columns mean?
# P N % SE D G R A
001 23 13 .64 56 06 2 2 19
002 21 22 .49 24 10 2 1 20
003 19 30 .39 60 04 1 4 1
004 24 07 .77 80 06 2 1 23
005 29 31 .48 64 01 1 2 21
006 17 30 .36 80 09 2 1 20
007 10 24 .29 24 12 1 1 20
008 39 16 .71 40 05 1 1 25
009 28 18 .61 68 02 1 2 19
010 07 24 .23 36 09 2 4 34
011 07 30 .19 40 15 2 1 17
012 09 86 .10 16 36 2 4 30
013 27 24 .53 72 08 2 1 20
014 26 06 .81 80 00 2 1 30
015 28 13 .68 72 02 1 1 20
016 07 23 .23 60 22 2 1 21
017 16 37 .30 52 15 1 1 21
018 30 09 .77 84 06 2 1 19
019 19 34 .36 56 09 1 1 19
020 21 29 .42 64 13 1 1 20
Click here to see answer by stanbon(26259) |
Question 83528: Jill picked a letter from the word "WIN" at random and then picked a letter from thw word "GAME" at random
a) Draw a tree diagram or list a sample space showing all possible outcomes
b) Find the probability that
1) one of the letters chosen was an "N" and the other was an "M"
2) one of the letters chosen was a "W" and the other was a vowel
3) at least one letter chosen was a vowel
4) neither letter chosen was a vowel
PLease Help!!
Click here to see answer by stanbon(26259) |
Question 83651: In a package of candy coated chocolates, 30 percent of the candies are brown, 20% of them are yellow, and 20% of them are red, there are 10% each of orange, green,and blue. if Ronan reaches into a package and pulls out 12 candies, what is the probability that
A) Exactly 2 of them would be red
B) at most 2 of them would be red
C) none of them would be blue
Round your answers to the nearest tenth of a percent.
Click here to see answer by stanbon(26259) |
Question 83665: the test scores in Mrs. kaste's Math b class are normally distributed with a mean of 85 and a standard deviation of 5. between what two scores would 95.4 percent of the scores fall?
75-100
80-90
75-95
85-90
Click here to see answer by stanbon(26259) |
Question 83883: Hello...
If the 5 cards shown above (each is different) are placed in a row so that the highlighted one (in the center in this diagram) is never at either end, how many different arrangements are possible?
Click here to see answer by stanbon(26259) |
Question 83903: Please help me with this statistical problem.
A manufacturer claims that the mean lifetime, u , of its light bulbs is 53 months. The standard deviation of these lifetimes is 8 months. Seventy bulbs are selected at random, and their mean lifetime is found to be 54 months. Can we conclude, at the 0.05 level of significance, that the mean lifetime of light bulbs made by this manufacturer differs from 53 months?
Thanks!
Click here to see answer by stanbon(26259) |
Question 83910: please help me with this statistical problem. An automobile assembly line operation has a scheduled mean completion time,u , of 13.4 minutes. The standard deviation of completion times is 1.7 minutes. It is claimed that, under new management, the mean completion time has decreased. To test this claim, a random sample of 90 completion times under new management was taken. The sample had a mean of 13.3 minutes. Can we support, at the 0.005 level of significance, the claim that the mean completion time has decreased under new management? Assume that the standard deviation of completion times has not changed.
Perform a one-tailed test.
Thanks!
Click here to see answer by stanbon(26259) |
Question 83945: This is a Linear Programming question
Find the soloution for
Maximizing Z = 2X+Y subject to constraints X is greater then or equal to 0; Y is greater then or equal to 0; x + 2y less then or equal to 4
Maimum Z =
Soloution = ( , )
Click here to see answer by stanbon(26259) |
Question 84218This question is from textbook elementary statistics in social research
: Alight I kinda get the gist of what is going on with this problem but i'm having a hard time with the mean deviation which would mean I will have a hard time with the variance and standard deviation.
A focus group of 10 adults was chosen to evaluate the performance of a candidate during a presidential debate. Each member of the group rated the overall perfomance on a scale of 1 (poor) to 10 (superior). The ratings given the canidate were as follows:
4 5 8 7 9 8 7 3 6 7
Range 9-3=6 so the range is 6.
Mean deviation
I am not sure how to do this part at all...or the variance and standard devation part. please can you help.This question is from textbook elementary statistics in social research
Click here to see answer by venugopalramana(3286)  |
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