random

4,662 results, page 31

1. Stat

Kindergarten children have heights that are approximately distributed normal. A random sample of size 20 is taken and the mean x and the standard deviation s are calculated ( x = 40 inches and s = 3). a. Is there sufficient evidence to indicate that the mean of kindergarten ...
2. Maths

In a box of markers there are eight which have dried up and will not write. The box contains 15 red, 15 purple, 5 black and 10 white markers. A marker is picked at random from the box. Find the probability that a) it is red b) it is not black c) it is purple or white d) it is ...
3. statistics

At a certain college, 15% of the students receieved an A in their required math cousre, 10% receieved an A in their required chemistry course, and 5% receieved an A in both. A student is selected at random. a.) What is the probability that he received an A in either chemistry ...
4. statistics

A random sample of 36 statistics students were asked to add a column of numbers. The amount of time required to compute the sum was recorded for each student. The sample mean time was 54 seconds with a sample standard deviation of 18 seconds. 1. Construct a 95% confidence ...
5. Statistics

The national centre of health statistics reports that the mean systolic blood pressure for males 35-44 years of age is 128 and a standard deviation of 15. A group of 50 executives selected at random are tested and found to have an avarage of 132.3. Is there statistical ...
6. statistics

In 2000, National data suggested that 26% of all U.S. businesses were owned by women. In 2009, a consulting firm surveyed a random sample of 700 U.S. businesses and found that 28% of them were owned by women. Is this evidence of an increase in the percentage of businesses that...
7. Statictics

6. In 2000, the United Nations claimed that there was a higher rate of illiteracy in men than in women from the country of Qatar. A humanitarian organization went to Qatar to conduct a random sample. The results revealed that 45 out of 234 men and 42 out of 251 women were ...
8. Stats

Among 15,378 Delta airline passengers randomly selected, 3 were bumped from a flight against there wishes (based on data from the us dept of transportation) find the probability that a random selected passenger is involuntarily bumped. Is such bumping unusual? Does such ...
9. probability April-004

In a random sample of 95 sections of pipe in a chemical plant, 16 showed signs of serious corrosion. Construct a 98% confidence interval for the true proportion of pipe sections showing signs of serious corrosion, using the large sample confidence interval formula.
10. statistics

1000 raffle tickets are sold and the winner is chosen at random there is only one prize \$500 in cash you buy one ticket(a) what is the probability you will win the prize of \$500 (b) your expected earnings can be found by multiplying the value of the prize by the probability ...
11. Math

In a recent year there were the following numbers (in thousands) of licensed drivers in the United States. MALE: Age 19 and under - 4746 Age 20 - 1625 Age 21 - 1679 FEMALE: Age 19 and under - 4517 Age 20 - 1553 Age 21 - 1627 Choose one driver at random. Find the probability ...
12. stats

The number of cars sold annually by used car salespeople is normally distributed with a standard deviation of 19.22. A random sample of salespeople was taken and the number of cars each sold is listed her. 79 43 58 66 101 63 79 33 58 71 60 101 74 55 88 The 95% confidence ...

Given the following information about a hypothesis test of the difference between two means based on independent random samples, which one of the following is the correct rejection region at a significance level of .05? Assume that the samples are obtained from normally ...
14. math

The table below shows the number of deaths in the U.S. in a year due to a variety of causes. For these questions, assume these values are not changing from year to year, and that the population of the United States is 312 million people. Cause Deaths Passenger car occupant 13,...
15. statistics

In a city, 20% of the workers have incomes over \$40,000 per year. A researcher chooses 1600 workers at random (with replacement) and finds that the mean is 320 and standard deviation is 16. what is the chance that between 320 and 336 of those have incomes over \$40,000 per year?
16. Statistic

A local eye clinic has two doctors. Dr. Kutallot recommends glass 60% of the time and corrective surgery 40% percent of the time. Dr. Lenzie recommends glasses 70% of the time and 30% of the time. 60% of the patients are treated by Dr. Lenzie. No patients are treated by both ...
17. math/statistics

In a manufacturing plant, three machines, A, B, and C, produce 37%, 36%, and 27%, respectively, of the total production. The company's quality-control department has determined that 1.5% of the items produced by Machine A, 2% of the items produced by Machine B, and 2.5% of the...
18. statistics

the manufacturer of a popular brand of tv set claims that 95 percent of its sets last at least 5 years without requiring a single repair. a sample of 8 purchasers of these tv sets was selected at random from a list of purchasers five years earlier. use this information to ...
19. statistics

The director of an inner-city hospital believes that the average cost per gunshot injury of patients admitted to the hospital’s emergency room is \$18,000. A random sample of 9 gunshot injuries had a mean of \$17,213 with a standard deviation of \$572. Calculate the ...
20. word problem

A study reported that in a random sampling of 100 women over the age of 35 showed that 8 of the women were married 2 or more times. Based on the study results, how many women in a group of 5000 women over the age of 35 would likely be married 2 or more times.
21. Statics

17. The Student Health Service assumes, based on historical data, that the height of female students is normally distributed with a standard deviation of 3 inches. The school nurse wants to estimate the average height of this year’s entering female students by examining the ...
22. Math - Stats

An experiment was conducted where rats could choose to enter one of two corridors, A or B. A random sample of three rats is selected. Let x = number of rats that select corridor B. Assuming the rats select their favorite corridor independently of one another and that the two ...
23. math

35% of North Americans do not think that college education is a contributory factor to economic success. A random sample of seven North Americans is selected. Find the probability that: a. Exactly 3 people will agree with that position (taken by the 35% of the population) b. ...
24. math

35% of North Americans do not think that college education is a contributory factor to economic success. A random sample of seven North Americans is selected. Find the probability that: a. Exactly 3 people will agree with that position (taken by the 35% of the population) b. ...
25. stat probability

An apartment building has the following apartments: 2 bdrm 3 bdrm 4 bdrm 1st floor 7 3 4 2nd floor 9 0 11 3rd floor 8 4 7 If an apartment is selected at random, what is the probability that it is a 2 bedroom apartment on the 3rd floor?
26. statistics

Question 1 A school psychologist reports that the mean number of hours the students at this school sleep each night is 8 hours. The students believe the mean is not 8 hours. To find an estimate of the true mean, they select a random sample of 15 students from their school and ...
27. Statistics

Data in 1980 showed that about 48% of the adult population had never smoked cigarettes. In 2004, a national health survey interviewed a random sample of 5000 adults and found that 54% had never been smokers. Create a 95% confidence interval for the proportion of adults in 2004...
28. Math

In Exercises 16–18, use the following information. At a college, 43% of the students are women, 15% of the students are art majors, 4% have not chosen a major, and 8% are women and art majors. A faculty member conducts an experiment and selects students at random to ...
29. Statistics

Jim's systolic blood pressure is a random variable with a mean of 145 mmHg and a standard deviation of 20 mmHg. For Jim's age group, 140 is the cutoff for high blood pressure. If Jim's systolic blood pressure is taken at a randomly chosen moment, what is the probability that ...
30. statistics

An assembly process includes a torque wrench device that automatically tightens compressor housing bolts; the device has a known process standard deviation of ó = 3 lb-ft in the torque applied. A simple random sample of 35 nuts is selected, and the average torque to which ...

The average length of a flight by regional airlines in the United States has been reported as 299 miles. If a simple random sample of 30 flights by regional airlines were to have ȭ = 413/6 miles and s= 42.8 miles, would this tend to cast doubt on the reported average of...
32. math

Independent random samples, each containing 800 observations, were selected from two binomial populations. The samples from populations 1 and 2 produced 320 and 400 successes, respectively. Construct a 90% confidence interval for the true difference in population proportions ...
33. Statistics- Standard Error

A population of 200 voters contains 52 Republicans, 128 Democrats, and 20 independents and members of other parties. A simple random sample of 20 voters will be drawn from this population. The expected number of Republicans in the sample is ______ ? The standard error of the ...
34. maths- probabilty(me posted third time)plse answer

There are two bags out of which Bag 1 contains 2 white and 3 red balls and bag 2 contains 4 white and 5 red balls. 1 ball is drawn at random from one of the bags and is found to be red. Find the probability that it was drawn from bag 2
35. statistics

Find the indicated binomial probabilities. Round to the nearest 3 decimal places. In a local college, 20% of the math majors are women. Ten math majors are chosen at random. 1) What is the probability that exactly 2 are women? 2) What is the probability that 2 or less women ...
36. Random

A room has five corners, one of the five has an angle is 179 degrees what would be the measure meant of the other angle if the sum of two of the unknown angles is 60 and the sum of the other two is 3 less than the sum of the first two. my first question is, IS THIS EVEN ...
37. Statistics

According to a recent survey, 65% of all customers will return to the same grocery store. Suppose 11 customers are selected at random,what is the probability that A) exactly 5 will return? B) all 11 will return? C) at least 6 will return D) at least one will return E) how many...
38. Maths

A contains some red and blue balls. There are four more red than blue balls. A ball is removed at random and replaced. A second ball is removed. The probability that the two balls are different colours is 21/50. How many balls are in the box. Ans Drawing a tree diag gives you ...
39. Math

Can someone guide me with this question? Four teachers and five students have volunteered to serve on the school's fundraising committee, which is chaired by the principal. The principal wishes to select the committee using a random draw. He places each person's name on a slip...
40. Psychology

Consider the interpretation of psychological findings. You are taking a multiple choice assessment, similar to this one, when you encounter a quandary. You see a series of four possible answer choices, two of which seem very plausible conclusions. What do you do? Answer ...
41. statistics

air coin is flipped 20 times. a. Determine the probability that the coin comes up tails exactly 15 times. b. Find the probability that the coin comes up tails at least 15 times. c. Find the mean and standard deviation for the random variable X giving the number of tails in ...
42. Statistics

Let X1;X2;X3;...;X6 be a random sample from a distribution with the following probability desity function: Fx(x) = (1+4x)/3 for 0<x<1 = 0 for x=<0; x>=1. (a) Determine the joint p.d.f of Y1 and Y6 where Y1<Y2<...Y6 are the order statistics. (b) Let R= Y6-Y1 ...
43. Math : Probability and Standard Deviation

This is a word problem. "We know that for certain workers the mean wage is \$5/hr with a standard deviation of \$.50. We need to find out if a worker is chosen at random what is the probability that the workers' wage is between \$4.50 and \$5.50? Assume a normal distribution of ...
44. Math

A florist sold bouquet of red roses to 15 of the first 20 customers who came into his shop. 1. What is the experimental probability that a random customer in that group bought a bouquet of red roses? 2. Based on the experimental probability, how many bouquets of red roses ...
45. Math

A florist sold bouquet of red roses to 15 of the first 20 customers who came into his shop. 1. What is the experimental probability that a random customer in that group bought a bouquet of red roses? 2. Based on the experimental probability, how many bouquets of red roses ...
46. statistics

A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 121.2-cm and a standard deviation of 1.8-cm. Suppose a rod is chosen at random from all the rods produced by the company. There is a 23% probability that the rod is longer than...
47. Probability

The signers of the declaration of Independence came from the 13 colonies as shown: Massachusetts: 5 New Hampshire: 3 Virginia: 7 Maryland: 4 New Jersey: 5 Pennsylvania: 9 Rhode Island: 2 New York: 4 Georgia: 3 North Carolina: 3 South Carolina: 4 Connecticut: 4 Delaware: 3 ...
48. PHYSICS

can someone help me with physics lab homework please: load 300 g at 60 degree mass at 180 deg 150 g mass at 270 deg 260 g for step two resolution of 300-g at 60 degree f load= fx'= fy'= percent error for each component for setup II? WOULD THE HYPOTHETICAL SITUATION DESCRIBED ...
49. statistics

10th grade New York public school students taking a standardized English test produced test scores that were normally distributed with a mean of 85 and a standard deviation of 4. Let x be a random variable that represents the test score of a student. Students whose test scores...
50. Math

A 10-in2 section of a 25-in2 dartboard is painted red. If a dart lands at random on the dartboard, what is the probability that it lands in the section painted red?
51. statistics

A city survey found that 47% of teenagers have a part time job. The same survey found that 78% plan to attend college. If a teenager is chosen at random, what is the probability that the teenager has a part time job and plans to attend college?
52. statistics

Suppose that 65% of all California State students own a motorcycle. A random sample of 100 CS students is surveyed and 61% indicate that they own a motorcycle. a. What is the value of the population percent given to you in the problem? b. What is the value of the sample ...
53. statistics

Suppose that 65% of all California State students own a motorcycle. A random sample of 100 CS students is surveyed and 61% indicate that they own a motorcycle. a. What is the value of the population percent given to you in the problem? b. What is the value of the sample ...
54. Statistics

Suppose the mean income of 35-year-olds in the US is \$25,000. A random sample of 150 35-year-olds in California results in a sample mean income of \$26,600 and a sample standard deviation of \$3800. At the 5% significance level, ca we conclude that the true mean income of 35-...
55. Math

What price do farmers get for the peach crops? in the third week of June, a random sample of 40 farming regions gave a sample mean of \$6.88 per basket. assume that the standard deviation is known to be \$1.92 per basket. find a 90% confidence interval for the population mean ...
56. Statistics

The monthly incomes from a random sample of workers in a factory are shown below. Monthly Income (In \$1,000) 4.0 5.0 7.0 4.0 6.0 6.0 7.0 9.0 a. Compute the standard error of the mean (in dollars). b. Compute the margin of error (in dollars) at 95% confidence. c. Compute a 95% ...
57. Probability

Given additional information that 56% of the total employees in the company are male and 50% of them are employees who have been working less than 5 years. If an employee selected at random is known to have been working for 5 years or more, what is the probability that the ...
58. Statistics

From a random sample of 500 registered voters in Los Angeles, 400 indicated that they would vote in favour of a proposed policy in an upcoming election. a) Test at the 10% significance level a politician’s statement that “those who are in favour of this policy represent ...
59. Psychology

HELP !!! Which statistics concept is described? Choose from these answers: [(A):statistical test] [(B):Null Hypothesis] [(C):alpha] [(D):one-tailed test] [(E):two-tailed test] [(F):Type I error] [(G):Type II error] [(H):the statistic Z] 1)When a hypothesis is that two groups ...
60. random

this website is so helpful but i am confused on some things 1) the people who answer questions is this their job or are they volunteering to for free and what do they gain out of this 2)do the tutors who answer questions sit at home and answer or at some work place 3) how ...

An assembly process includes a torque wrench device that automatically tightens compressor housing bolts; the device has a known process standard deviation of ó = 3 lb-ft in the torque applied. A simple random sample of 35 nuts is selected, and the average torque to which ...

An assembly process includes a torque wrench device that automatically tightens compressor housing bolts; the device has a known process standard deviation of ó = 3 lb-ft in the torque applied. A simple random sample of 35 nuts is selected, and the average torque to which ...
63. Algebra 2

Garrett thros a dart at a circular dart board. the dart board has a radius of 16 inches, and the bull's eye in the center of the dart board has a radius of 6 inches. What is the probability that a dart thrown at random within the dartboard will hit the bull's eye?
64. statistic

1.The state highway patrol stops every 5th car on highway 210 to check drivers' licenses and registrations. Which sampling technique are they using? systematic sampling -chose this one convenience sampling cluster sampling simple random sampling stratified sampling 2.You ...
65. Statistics

According to a recent survey, 65% of all customers will return to the same grocery store. Suppose 11 customers are selected at random,what is the probability that A) exactly 5 will return? B) all 11 will return? C) at least 6 will return D) at least one will return E) how many...
66. math

A random sample of dogs at different animal shelters in a city shows that 12 of the 60 dogs are puppies. The city's animal shelters collectively house 1,200 dogs each year. About how many dogs in all of the city's animal shelters are puppies? THANK YOU!
67. Science-Chemistry

1)Fill in the blanks. In a liquid, particles are _____arranged. They move about in ____ directions and slide over one another. Can I say "irregularly" & "any" as the answers? I know "random directions" is better, but can we accept "any directions"? 2) When water at 30ËšC is ...
68. Statictics

2. Herpetologists (snake specialists) found that a certain species of reticulated python have an average length of 20.5 feet with a standard deviation of 2.3 feet. The scientists collect a random sample of 30 adult pythons and measure their lengths. In their sample the mean ...
69. Statistics

(1) Gluten sensitivity, which is also known as wheat intolerance, affects approximately 15% of people in U.S. Let p be the proportion in a random sample of 800 individuals who have gluten sensitivity. Find the probability that the value of p is (a) Within 0.02 of the ...
70. hostos

the average math sat score is 500 with a standard deviation of 100. a particular high school claims that its students have usually high math SAT scores a random sampel of 50 students from this school was selected, and the mean math sat score was 530 . Is the high school ...
71. Stats

Determine the following random variables discrete or continuous: a)Number of fish I caught during 2 hours? I said: discrete b)Temperature of a coffee cup? I said: continuous c)Height of a 2-year-old maple tree? I said: continuous d) Number of credit cards I have in my wallet? ...
72. Math

Let X and Y equal the respective numbers of hours a randomly selected child watches movies or cartoons on TV during a certain month. From experience, it is known that E(X) = 30, E(Y) = 50, Var(X) = 52, Var(Y) = 64, and Cov(X, Y)= 14. Twenty-five children are selected at random...
73. Probability & Statistics

You want to rent an unfurnished one-bedroom apartment in Boston next year. The mean monthly rent for a random sample of 14 apartments advertised in the local newspaper is \$1200. Assume that the standard deviation is \$230. Find a 95% confidence interval for the mean monthly ...
74. Math

9 fair coins are independently tossed in a row. Let X be the random variable denoting the number of instances in which a Head is immediately followed by a Tail during these 9 tosses. The variance of X has the form ab, where a and b are coprime integers. What is the value of a+...
75. Math

9 fair coins are independently tossed in a row. Let X be the random variable denoting the number of instances in which a Head is immediately followed by a Tail during these 9 tosses. The variance of X has the form a/b, where a and b are coprime integers. What is the value of a...
76. statistics

twenty light bulbs are tested to see if they claims last long as the manufacturers claims they do. three light bulbs failed the test. two light bulbs are selected at random without replacement from this collection of bulbs find the probability that both light bulbs failed the ...
77. statistics

The average math SAT score is 500 with a standard deviation of 100. A particular high school claims that its students have unusually high math SAT scores. A random sample of 50 students from this school was selected, and the mean math SAT score was 530. Is the high school ...
78. ci

A researcher is interested in whether students who attend private high schools have higher average SAT Scores than students in the general population. A random sample of 90 students at a private high school is tested and and a mean SAT score of 1030 is obtained. The average ...
79. Math: Geometry

Of 162 students honored at an academic awards banquet, 48 won awards for mathematics and 78 won awards for English. There are 14 students who won awards for both mathematics and English. A newspaper chooses a student at random for an interview. What is the probability that the...
80. stats

In a straight 3 lottery you choose a 3 digit number. A 3 digit number is chosen at random, If your number mataches you win \$250. 1. How many diifrent three digit numbers are there? I thought you would do 3^3 but that only equaled 27 so i assumed im wrong 2. what is the ...
81. statistics

An ordinary (fair) die is a cube with the numbers 1 through 6 on the sides (represented by painted spots). Imagine that such a die is rolled twice in succession and that the face values of the two rolls are added together. This sum is recorded as the outcome of a single trial ...
82. Statistics

a random sample of 10 minature tootsie rolls was taken from a bag. Each piece was weighed on a very accurate scale. The results in grams were 3.087, 3.131,3.241,3.270,3.353,3.400,3.411,3.437,3.477 a.) construct a 90 percent confidence intervalfor the true meam weight. b.)what ...
83. Statistics

Suppose that the probability distribution of a random variable x can be described by the formula P(x) = x/15 For each of the values x = 1, 2, 3, 4, and 5. For examples, then, p(x=2) = p(2) = 2/15 a Write out the probability distribution of x. b Show that the probability ...
84. STATS

The top selling Red and Voss tire is rated 70,000 miles means nothing. In fact, the distance the tires can run until they wear out is a normally distributed random variable with a mean of 82,000 miles and a standard deviation of 6,400. a. What is the probability that a tire ...
85. maths-probabilty(URGENTLYYY)

There are two bags out of which Bag 1 contains 2 white and 3 red balls and bag 2 contains 4 white and 5 red balls. 1 ball is drawn at random from one of the bags and is found to be red. Find the probability that it was drawn from bag 2
86. College Math

In a group of 200 high school students, 36 are taking biology, 52 are taking Spanish, and 126 are taking neither biology nor Spanish. If one of these 200 students is to be chosen at random, what is the probability that the student chosen is taking biology but not Spanish?
87. college intermediate

In a group of 200 high school students, 36 are taking biology, 52 are taking Spanish, and 126 are taking neither biology nor Spanish. If one of these 200 students is to be chosen at random, what is the probability that the student chosen is taking biology but not Spanish?
88. astronomy

Which statement gives the relationship between the waves in the electric and magnetic fields in an electromagnetic wave? a)they are in phase and parrallel to each other in space b)they are 90 degrees out of phase but parrallel in space c)they are in phase but perpendicular to ...
89. Probability

A box contains 3 blue, 5 red, 4 white marbles. If one marble drawn at random: find probability of blue given not white. Find probability of not red given not white
90. MATH/Probability

our different written driving tests are administered by the MVD. one of these four tests is selected at random for each applicant for a drivers test. if a group consisting of two women and three men apply for a license, what is the probability that a. exactly two of the five ...
91. Math 7th grade

Susan has red, blue, and yellow sweaters. Joanne has green, red, and white sweaters. Diane's sweaters are red, blue, and mauve. Each girl has only one sweater of each color and will pick a sweater to wear at random. Find the probability that each girl chooses a different color...
92. statistics

A company assembles drills using components from two sources. Acemart supplies 91% of the components and Begud supplies the rest. It is known that 6% of the components supplied by Acemart are faulty and 3% of those supplied by Begud are faulty. a) represent this info on a tree...
93. math

B) A random sample of 16 mid-sized cars tested for fuel consumption gave a mean of 26.4Kilometers per liter with a standard deviation of 2.3 kilometers per liter. i) Assuming that the kilometers per liter given by all mid-sized cars have a normal distribution, find a 99% ...
94. Statistics

The mean grade in this class last semester was 78.3, and the variance was 49 . The distribution of grades was unimodal and symmetrical. Using this information determine the probability that “Joe”, a random student you know nothing about, other than the fact that they are ...
95. probability

A jar contains 3 red balls and 2 green balls. You draw one ball at random. Determine the probability of selecting a. red b. green c. blue d. red or green p.s: the reason I am asking this questions is because we never learned about it in class and I don't know how to do it; so ...
96. Stats

Suppose that a random sample of adults has a mean score of on a standardized personality test, with a standard deviation of . (A higher score indicates a more personable participant.) If we assume that scores on this test are normally distributed, find a confidence interval ...
97. Statistics

Let x and y be the amounts of time (in minutes) that a particular commuter must wait for a train on two independently selected days. Define a new random variable w by w = x + y, the sum of the two waiting times. The set of possible values for w is the interval from 0 to 2a (...
98. Statistics

In a random sample of 50 undergraduate students at a college, it was found that 44 students regularly access social networking websites from their college library. What is the margin of error for the true proportion of all undergraduates who access social networking sites from...
99. Statistics

M&M plain candies come in various colors. According to the M&M/Mars Department of Consumer Affairs, the distribution of colors for plain M&M candies is as follows. Color Purple Yellow Red Orange Green Blue Brown Percentage 18% 19% 21% 9% 9% 6% 18% Suppose you have a large bag ...
100. Statistics

Dr. Hernandez plans to measure FEV in a random sample of n young women from a certain popu- lation, and to use the sample mean y ̄ as an estimate of the population mean. Let A be the event that Hernandez’s sample mean will be within ±100 ml of the popula- tion mean. ...