Sunday

April 19, 2015

April 19, 2015

Number of results: 14,620

**Math Statistics**

3. Suppose 20% of all heart transplant patients do not survive the operation. a. Think about taking repeated random samples of 371 patients from this population. Describe how the sample proportion who die would vary from sample to sample. (Hint: Be sure to refer to the shape, ...
*July 22, 2013 by TCaesar*

**statitics**

Suppose that a sample of n = 1,600 tires of the same type are obtained at random from an ongoing production process in which 8% of all such tires produced are defective. What is the probability that in such a sample 150 or fewer tires will be defective
*March 27, 2012 by Chris*

**statitics**

Suppose that a sample of n = 1,600 tires of the same type are obtained at random from an ongoing production process in which 8% of all such tires produced are defective. What is the probability that in such a sample 150 or fewer tires will be defective
*March 27, 2012 by Chris*

**Math**

Having trouble knowing where to start with this one: A maker of tools claims the average amount of time it takes to assemble a table saw is 50 mins with a standard deviation of 40 mins. What is the probability that the sample mean will be less than 44 mins if a random sample ...
*March 23, 2010 by Len*

**statistics**

Scores on a certain test are normally distributed with a variance of 91. A researcher wishes to estimate the mean score achieved by all adults on the test. Find the sample size needed to assure with 95.44 percent confidence that the sample mean will not differ from the ...
*June 25, 2011 by vina*

**statistics**

From a shipment of 350 batteries, a sample of 125 was selected at random and tested. If 25 batteries in the sample were found to be dead, how many dead batteries would be expected in the entire shipment?
*February 13, 2013 by Anonymous*

**statistics**

Assume a simple random sample has been taken, the conditions for binomial distribution are met and the sample proportions can be approximated by a normal distribution. In order to evaluate a course of therapy to treat brain tumors, a sample of 300 patients revealed that 96 ...
*December 5, 2012 by Ox*

**statistics**

Assume a simple random sample has been taken, the conditions for binomial distribution are met and the sample proportions can be approximated by a normal distribution. In order to evaluate a course of therapy to treat brain tumors, a sample of 300 patients revealed that 96 ...
*December 5, 2012 by Ox*

**statistic****help*******

Show all your work. Indicate clearly the methods you use because you will be graded on the correctness of your methods as well as on the accuracy of your results and explanation. A simple random sample of adults living in a suburb of a large city was selected. The age and ...
*March 19, 2014 by akiba*

**statistics**

Suppose that large dogs weights are normally distributed with a mean of 100 pounds and a standard deviation of 10 pounds. If one of these dogs is picked random: a) what is the probability that the dog will weigh over 110 pounds? b) what is the probability that the dog will ...
*March 26, 2010 by Anonymous*

**Math**

A vending machine has marbles of 4 different colors: Red, blue, purple,and yellow. The marbles are well mixed. You drop a quarter into the machine and you get 2 random marbles. Write out the sample space for the experiment. The sample space should be N = 10.
*July 11, 2012 by Meredith*

**statistical applications**

when is random sampling not the best approach to sample selection?
*March 8, 2010 by anette*

**math **

Find the probability between 42 and 48 speeders in a random sample of 100
*May 2, 2013 by john jones*

**statistics**

A manufacturer wishes to estimate the reliability (in months) of a certain product. An estimate of the population standard deviation from a previous sample was 12 months. If the manufacturer desires to be within 4 months of the true value with approximately 80% confidence, ...
*November 8, 2011 by Larry*

**STATISTIC***HELP**

Show all your work. Indicate clearly the methods you use because you will be graded on the correctness of your methods as well as on the accuracy of your results and explanation. A simple random sample of adults living in a suburb of a large city was selected. The age and ...
*March 18, 2014 by KIBA*

**statistics**

You are a travel agent and wish to estimate, with 98% confidence, the proportion of vacationers who use an online service or the Internet to make travel reservations. Your estimate must be accurate within 4% of the population proportion. a) No preliminary estimate is available...
*April 6, 2011 by alex*

**maths**

a box contains 20 fuses ,out of which ,5 are defective.if a sample of 3 fuses is chosen from the box at random without replacement,find the probability that x fuses in this sample will be defective
*February 11, 2012 by ashely*

**statistics**

How does the sample size differ between qualitative and quantitative methods? Why?
*October 20, 2008 by nicky*

**statistics**

2. How does the sample size differ between qualitative and quantitative methods? Why?
*October 22, 2008 by nicky*

**statistics**

If a sample of size 30 is selected, the value of A for the probability P(t greater or less A) = 0.01 is?
*August 1, 2009 by Lina*

**statistics**

Population Mean: 170 STD: 62.3 Sample size 100 95% CI 99%CI
*February 10, 2014 by Anonymous*

**statistic**

For a given month, a random sample of 30 sales girls from a superstore has a sample mean of salary of RM 800 with standard deviations of RM 140. Estimate the mean monthly salary for all employees using the 95% confidence interval.(what does mean of 95% confidence level?)
*September 27, 2011 by niki*

**algebra**

in triangle ABC, the size of angle B is 5 times the size of angle A and the size of angle C is 9 degrees less than 4 times the size of angle A Find the size of angle A
*February 17, 2012 by Anonymous- boy*

**math**

identify the variable, population and is this quantitative or qualitative The archaeological site of Tara is more than 4000 years old. Tradition states that Tara was the seat of the high kings of Ireland. Because of it's archaeological importance, Tara has received extensive ...
*June 8, 2013 by marie*

**Statistics**

I have another Stats question i'm confuesed on. classify the sample as random, systematic, covenience, stratified, or cluster. A marketing executive fo General Motors finds that its public department has just printed envelopes with the names and addresses of all Corvette ...
*January 21, 2013 by Gavin*

**Stats**

Recently, an automobile insurance company performed a study of a random sample of 15 of its customers to determine if there is a positive relationship between the number of miles driven and the age of the driver. The sample correlation coefficient is r=.38. Given this ...
*June 13, 2011 by Breezy*

**Business Statistics**

A firm claims that only 10% of it's accounts receivables are over 30 days past due. The bank that supplies working capital or interim loans to the firms is suspect of the figure and accordingly takes a random sample of 100 accounts of the firm. Find the probability that the ...
*March 16, 2015 by Leo Elvis*

**AP Stat**

A random sample of 15 people is taken from a population in which 40% favour a particular political stand. What is the probability that exactly 6 individuals in the sample favour this political stand? 0.4000 0.5000 0.4000 0.2066 0.0041
*November 24, 2009 by Cb*

**Math Stats**

Suppose that a random sample of n kernels of popcorn is taken and x of these kernels pop. The buyer wants to be 95% sure that the point estimate for p will be within 0.01.If no preliminary study is done to estimate p, how large a sample should the buyer use? If a preliminary ...
*March 28, 2012 by Apryl*

**Statisics **

I need help on this question i am confused. I don't think the answers i got are right The library checks out an average of 320 books per day, with a standard deviation of 75 books. Suppose a simple random sample of 30 days is selected for observation. What is the probability ...
*February 20, 2011 by Mike*

**Statistics**

a laptop manufacturer finds that the average time it takes an employee to load a laptop with software is 20 minutes with a standard deviation 8 minutes. suppose you take a random sample of 81 employees. the standard deviation of the sample mean is?
*October 6, 2014 by Kalyssa*

**Math**

will someone just double check my answers, please. Identify which types of sampling is used:random,stratified, systematic,convenience. 1. a sample consists of every 20th student who leaves the bookstore. answer:systematic 2. a pollster uses a computer to generate 500 random ...
*April 15, 2010 by Charlene*

**STATISTICS**

The number of boxes of girl scout cookies sold by each of the girl scout in a city has a distribution which is approximately normal with a mean=75 boxes and a standard deviation=30 boxes.... 1.) find the probability that scout chosen at random sold between 60 and 90 boxes. 2...
*August 10, 2011 by Mason*

**STATISTICS HELP PLEASE!**

suppose you wish to estimate a population mean based on a random sample of n observations, and prior experience suggests that sd=12.7. if you wish to estimate the mean correct to within 1.6, with probability equal to .95, how many observations should be included in your sample?
*November 15, 2010 by Courtney*

**statistics**

A psychologist wants to estimate the variance of employee test scores. A random sample of 18 scores had a sample standard deviation 10.4. Find a 90% confidence 2 interval for the population variance. What assumption, if any, have you made in calculating this interval estimate?
*November 9, 2011 by Janelle*

**Math**

At your summer with a research company, you must get a random sample of people from your town to answer a question about spending habits. Which of the following Methods is most likely to be random? a)You survey customers at the local shopping mall b)You survey people chosen ...
*May 28, 2014 by Dope Fresh Nation*

**statistics**

The average temperature in households is 67.6 degrees F. The standard deviation is 4.2 degrees F. A random sample of 51 households is to be selected What is the probability that the average of this sample will be within 1.4 STANDARD ERRORS of the population mean?
*September 28, 2012 by Kristin*

**stats of biologists**

a manufacturer claims that the life time of a certain brand of batteries has a varaince of 5000(hours)^2. a sample of 26 has a variance of 7200(hours)^2. assuming that it is reasonable to treat these data as a random sample from a normal population, test the manufacturer's ...
*February 14, 2013 by Aboli*

**Probability and Statistics**

A research psychologist believes that professional athletes tend to be more confident than the typical person. From previous testing, he knows that the scores for people in the general population are approximately normally distributed with a mean of 72 and standard deviation ...
*April 29, 2012 by Kim*

**Statistics 2 please give answers to the below ques**

According to a study conducted by a statistical organization, the proportion of americans who are satisfied with the way things are going in their lives is 0.82. Suppose that a random sample of 105 Americans is obtained. (Please answer the below and round to four decimals ...
*November 26, 2014 by LADO*

**statistics(please answer!)**

Find a t score (a) such that P( -a < t < a) = 0.95. Asume sample size n = 10.
*January 20, 2015 by cdizzle*

**statistics(please answer!)**

find a t score (a) such that P( -a < t < a) = 0.95. Asume sample size n = 10.
*January 20, 2015 by lovely*

**statistics**

A random sample of 384 people in Dalto City, a mid-sized city, revealed 112 individuals who work at more than one job. A second random sample of 432 workers from East Dettweiler, another mid-sized city, found 91 people who work at more than one job. To conduct a significance ...
*October 26, 2012 by Derp*

**statistics**

A random sample of 384 people in Dalto City, a mid-sized city, revealed 112 individuals who work at more than one job. A second random sample of 432 workers from East Dettweiler, another mid-sized city, found 91 people who work at more than one job. To conduct a significance ...
*November 4, 2012 by John*

**Statistics**

A random sample of 384 people in Dalto City, a mid-sized city, revealed 112 individuals who work at more than one job. A second random sample of 432 workers from East Dettweiler, another mid-sized city, found 91 people who work at more than one job. To conduct a significance ...
*November 5, 2012 by John*

**ap stats need help**

Continuous Random Variable, I Let X be a random number between 0 and 1 produced by the idealized uniform random number generator described. Find the following probabilities: a.P(0¡ÜX¡Ü0.4) b.P(0.4¡ÜX¡Ü1) c.P(0.3¡ÜX0.5) d.P(0.3(<X<0.5) e.P(0.226¡ÜX¡Ü0.713) f.What ...
*March 10, 2009 by chris*

**Statistics**

Hoping to lure more shoppers downtown, a city builds a new parking garage in the central business district. The city hopes that the parking revenues will pay for the garage. During a recent two month period (44 days), the city statistician calculated the 95% confidence ...
*November 10, 2013 by Katie*

**Statistics**

A large furniture store has begun a new ad campaign on local television. Before the campaign, the long term average daily sales were $24,819. A random sample of 40 days during the new ad campaign gave a sample mean daily sale of x(bar)=$25,910 with sample standard deviation s...
*May 9, 2012 by Matt*

**statistics **

A random sample of 150 investment bankers (population 1) had thirty percent who expressed dissatisfaction with their choice of career. A random sample of 200 financial analysts (population 2) had forty-two percent who expressed dissatisfaction. In testing the hypothesis that a...
*March 27, 2015 by Anonymous*

**business**

MGT635-1003B-04 International Business Operations Management Assignment Name: Unit 5 Individual Project Deliverable Length: 6-7 body pages Details: As the production manager for an electronic circuit company you have encountered the following situation. Part 1 A process for ...
*August 15, 2010 by 1SGCalhoun*

**statistics**

A simple random sample of 40 items resulted in a sample mean of 25. The population standard deviation is 5. a. What is the standard error of the mean (to 2 decimals)? b. At 95% confidence, what is the margin of error (to 2 decimals)?
*April 21, 2014 by Vanessa*

**Statistics**

How long does it take to have food delivered? A Chinese restaurant advertises that the mean delivery will be no more than 30` minutes. A random sample of delivery times is shown below. Based on this sample data, is the mean delivery time different than 30 minutes? Use a 5% ...
*March 25, 2012 by Jasmine*

**Data Structures and Algorithms**

The "random" numbers produced by computers aren't purely random. They are actually pseudo-random, meaning that they are produced by mathematical formulas that simulate randomness.The linear congruential generator takes a seed X0 and generates subsequent pseudo-random numbers ...
*July 22, 2013 by John Berkhamp*

**stats**

An automobile repair shop has determined that the average service time on an automobile is 2 hours with a standard deviation of 32 minutes. A random sample of 64 out of 400 services is selected. What is the probability that this sample will have a mean service time greater ...
*November 11, 2009 by sandy*

**Statistics**

A university has 1,000 computers available for students to use. Each computer has a 250-gigabyte hard drive. The university wants to estimate the space occupied on the hard drives. A random sample of 100 computers showed a mean of 115 gigabytes used with a standard deviation ...
*October 27, 2013 by Shelby*

**mba business reserach methods**

Sampling A manufacturing company's quality control personnel have recorded the proportion of defective items for each of 500 monthly shipments of one of the computer components that the company produces. See data below. The company doesn't have time to review all of these. (a...
*March 20, 2011 by Carolina*

**Statistics**

The null and alternate hypotheses are: H0: μ1 = μ2 H1: μ1 ≠ μ2 A random sample of 15 items from the first population showed a mean of 50 and a standard deviation of 5. A sample of 12 items for the second population showed a mean of 46 and a standard ...
*October 21, 2012 by Anonymous*

**statistics**

the assets (in billions of dollars)of the four wealthiest people in a particular country are 46,34,12,10. Assume that the samples of size 2 are randomly selected with replacement from this population of four values. After listing the possible sample and finding the mean of ...
*December 20, 2011 by nannie*

**statistics**

a recent study by a large retailer designed to determine whether there was a relationship between the importance a store manager placed on advertising and the size of the store revealed the following sample information: observed frequencies(sample)small-medium-large what kind ...
*February 23, 2012 by markeda*

**statistics**

Use the given confidence level and sample data to find a confidence interval for the population standard sigma. Assume that a simple random sample has been selected from a population that has a normal distribution. salaries of college graduates who took a geology course in ...
*December 29, 2011 by rich*

**statistics**

List below are the duration (in hours) of a simple random sample of all flights of a space shuttle program. Find the range, variance, and standard deviation for the sample data. Is the lowest duration time unusual? Why or hwy not? 73 95 238 199 166 268 198 374 260 235 382 339 ...
*October 29, 2013 by angela*

**Statistics**

The effect size in this hypothetical trial (2.7 fewer infections per 1000 vaccinated) is slightly smaller than the effect size found in the real 2009 HIV vaccine trial (2.8 fewer infections per 1000 vaccinated); so why is the p-value smaller? The hypothetical trial has less ...
*July 15, 2013 by Rupal*

**statistics**

A random sample of n=36 scores is selected from a population. Will this have a definite normal distribution?
*March 17, 2011 by Leticia*

**statistics**

A random sample of 100 of a population Mean is 31 and standard deviation 22 Approximate probability of 28
*April 27, 2013 by Dorri*

**statistics**

Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. The design of the study justifies the assumption that the sample can be treated as a simple random sample. Use the sample data to construct and ...
*July 7, 2014 by Teniqua Evans*

**Statistics**

Formula used to easily calcuate sample size. Please give example.
*January 26, 2010 by Bryant*

**statistics**

Sample size is 24, Mean rate of 6.50%, Standard Deviation is 1.20. Calculate 90% of confidence interval
*October 14, 2010 by sue*

**chemistry**

what sample size of .9181M vinegar would require 27.50 mL of .5185M of NaOH for neutralization?
*April 13, 2011 by maddie*

**Math**

Determine whether a correlation coefficient of r = –0.405 is significant at the 5% level for a sample size of 22
*January 27, 2012 by Constance*

**7th grade Math**

If there is a population of 800 deer what would be a good sample size and why.
*September 6, 2013 by Brandi*

**Math**

Determine whether a correlation coefficient of r = 0.471 is significant at the 5% level for a sample size of 20.
*July 12, 2014 by Shelagh*

**Math Help Please? c: Thank you :3 **

At your summer job with a research company, you must get a random sample of people from your town to answer a question about spending habits. Which of the following methods is most likely to be random? A) You survey customers at the local shopping mall. B) You survey people ...
*April 10, 2014 by X3 ISayRawr*

**STAT**

1. In a study of the income of U.S. factory workers, a random sample of 100 workers shows a sample mean of $35,000. Assume that the population standard deviation is $4,500, and that the population is normally distributed. A) Compute the 90%, 95% and 99% confidence intervals ...
*November 2, 2014 by Hugh*

**statistic**

Suppose a random sample of 25 students is selected from a community college where the scores in the final exam (out of 125 points) are normally distributed, with mean equal to 112 and standard deviation equal to 12. Find the probability that the sample mean deviates from the ...
*November 8, 2012 by Coco*

**Math please help**

According to a study conducted by a statistical organization, the proportion of americans who are satisfied with the way things are going in their lives is 0.82. Suppose that a random sample of 105 Americans is obtained. (Please answer the below and round to four decimals ...
*December 3, 2014 by LADO*

**Statistics**

(TCO A) Consider the following age data, which is the result of selecting a random sample of 20 United Airlines pilots. 47 45 45 52 58 55 58 44 42 38 45 52 48 47 51 45 52 42 37 40 a. Compute the mean, median, mode, and standard deviation, Q1, Q3, Min, Max for the above sample ...
*September 6, 2012 by Pat*

**statistics**

you are asked to estimate the average weight of an adult male passenger for a study to maximize the number of seats in a certain airplane. you collect random weights of 1000 men passengers from a population of 100,000. you find that the average man in the sample weighs 180 ...
*December 19, 2011 by KK*

**algebra**

55% of the people in a town have brown eyes. you choose a random sample of 200 people to survey regarding their eye color. What is the mean and standard deviation of the proportion of people in your sample that have brown eyes?
*January 16, 2011 by Anonymous*

**Statistics**

please help having difficulty with this problem. It was noted that 40% of the people in Dallas read the morning newspaper. A random sample of 18 people is selected from the city. On average, how many people would you expect to read the morning newspaper in a sample of 18?
*December 13, 2012 by Stacy*

**Statistics**

From random sample of 200 college students, 40 students indicated that they smoke cigarettes. Use the information from the sample to calculate a 95% confidence interval for the population proportion of college students that smoke cigarettes (round to nearest hundredth). A. (0....
*May 18, 2012 by Mary*

**Statistics**

A quality control inspector wants to estimate the mean inside diameter of the washers produced by a certain machine. A preliminary sample indicates that the inside diameters have a standard deviation of 0.30 millimeters. What sample size does he need to estimate the mean to ...
*December 6, 2012 by Carolyn*

**statistics**

Statistical Abstracts (117th edition) provides information aboutthe number of registered automobiles, including taxis, by state. The number ofregistered automobiles per 1,000 residents follows an approximately normaldistribution with mean ì = 514.6 and standard deviation ó = ...
*April 19, 2012 by Anonymous*

**Statistics**

Calculate the following: a) Determine the sample size necessary to estimate a population mean to within 1 with a 90% confidence given that the population standard deviation is 10. b) Suppose that the sample was calculated at 150. Estimate the population mean with 90% confidence.
*March 13, 2010 by Tom*

**STATS Math**

Suppose a simple random sample of size n=150 is obtained from a population whose size is N=20,000 and whose population proportion with a specified characteristic is p=0.8. Please answer questions (1) through (5) below. (1) describe the sampling ditriribution of p^ (choose the ...
*November 26, 2014 by LADO*

**AP Stats**

The mean weight of pears grown in a certain orchard is 6 ounces with a standard deviation of .5 ounces. A random sample of 30 pears is selected. What is the approximate probability that the sample mean weight is less than 5.5 ounces?
*April 25, 2010 by Lilly*

** Statistics**

Suppose we have yo estimate the average number of purchases in a given hour in a given hour at a convenient store. Using this example describe in your own words how you would go about this determining this average through: A.) Drawing a random sample B.) A Systematic sample C...
*February 9, 2015 by Phyiss*

**statistics**

According to the MIT Airline Data Project, American Airlines controlled 15.5% of the domestic market in 2010. A random sample of 125 domestic passengers that year was selected. Using the normal approximation to the binomial distribution, what is the probability that more than ...
*July 20, 2014 by james*

**Statistics **

Total plasma volume is important in determining the required plasma component in blood replacement theory for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that sample of some male firefighters ...
*July 7, 2012 by Desperate *

**statistics**

the weights of shells follow a normal distribution. a random sample of 12 hybrid shells a a mean weight of 1.7 pounds with standard deviation 0.24 pounds. Find a 95 % confidence interval level for the mean weight if the fall catch is within 0.1 pounds of the sample estimate
*March 21, 2013 by Lost37*

**Econ 112**

A researcher believes that the average size of farms in the U.S. has increased from the 2002 mean of 471 acres. She took a sample of 23 farms in 2011 to test her belief and found a sample mean of 498.8 acres and a sample standard deviation of 46.9 acres. At a 5% levelof ...
*June 18, 2013 by Help*

**Math**

What is the propability that a random sample of 30 days in august has a mean high tempature less then 78 degreese?
*October 30, 2010 by Sherrie*

**statistics**

Let X be the average of a sample of 16 independent normal random variables with mean 0 and variance 1. Determine c such that P (X< c) = .5
*March 9, 2011 by Anonymous*

**Statistics**

There is a random selection of 150 students. What is the probablity that the sample percentage of correct identification is greater than 75%?
*June 18, 2013 by Katie*

**Algebra 2: Prob and Stats**

Find the sample size that produces the margin of error +-4.0% a) 325 b) 25 c) 16 d) 625
*May 24, 2010 by Skye*

**statistical applicatons**

Why is it important to learn what sample size was used in a study in which no statistica difference was found?
*July 10, 2010 by Jerry*

**statistics**

What is the relationship between Sample Size and the width of the Confidence Interval? Please explain further as to why
*September 16, 2011 by denise*

**Stats Math 3**

Suppose a simple random sample of size n=150 is obtained from a population whose size is N=20,000 and whose population proportion with a specified characteristic is p=0.8. Please answer questions (1) through (5) below. (1) Describe the sampling distribution of p^ (choose the ...
*November 26, 2014 by LADO*

**statistics**

The ages of commercial aircraft are normally distributed with a mean of 13.0 years and a standard deviation of 7.5 years what percentage of individual aircraft have ages greater than 15 years assume that a random sample of 49 aircraft is selected and the mean age of the sample...
*April 24, 2012 by Tanya*

**statistics**

Listed below are the duration's (in hours) of a simple random sample of all flights of a space shuttle program. Find the range, variance, and standard deviation for the sample data. Is the lowest duration time unusual? Why or why not? 71 100 237 199 164 269 193 379 252 233 388...
*February 11, 2015 by slomo*

**STATISTICS PLEASE HELP!!!!!**

are you a chocolate "purist", or do you like other ingredients in your chocolate? american demographics reports that almost 75% of consumers like traditional ingredients such as nuts or caramel in their chocolate. they are less enthusiastic about the taste of mint or coffee ...
*November 3, 2010 by Brittany*