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April 16, 2014

Search: The tread life is normally distributed with a standard deviation of 295.5 kilometers

Number of results: 27,486

statistics
It is claimed that an automobile is driven on the average more than 20,000 kilometers per year. Random sample of 10 automobile owners are asked to keep a record of the kilometers they travel. If the sample mean and standard deviation of automobile driven are found to be 23,500...
Friday, June 3, 2011 at 5:35pm by Ali

prob and stats
The tread lives of the Super Titan radial tires under normal driving conditions are normally distributed with a mean of 34000 mi and a standard deviation of 1700 mi. (a) What is the probability that a tire selected at random will have a tread life of more than 35071 mi? Round ...
Friday, October 15, 2010 at 1:14am by br0Ok3

Statistics
find the 90% confidence interval for the variance and standard deviation of a sample of 16 and a standard deviation of 2.1 Assume the variable is normally distributed.
Sunday, October 24, 2010 at 10:56pm by Anon

math
a tire manufacturer believes that the tread life of its tires are normally distributed and will lst an average of 60,000 miles with a standard deviation of 3,000 miles. sixty-four randomly selected tires were tested and the average miles where the tire failed were recorded. ...
Tuesday, May 31, 2011 at 7:02pm by monk

Statistics
9 points) In a normally distributed data set, find the value of the standard deviation if the following information is given. a. The mean is 226.2. x = 230. z = 0.2. Standard deviation
Tuesday, April 1, 2014 at 10:18pm by Sarah Nichols

statistics
A construction zone on Kings Road has a posted speed of 45 kilometers per hour. The speeds of vehicle passing through this construction zone are normally distributed with a mean of 46 kilometers per hour and a standard deviation of 4 kilometers per hour. Find the percentage ...
Friday, May 11, 2012 at 12:53am by Nesa

Statistics
he life expectancy of a lung cancer patient treated with a new drug is normally distributed with a mean of 4 years and a standard deviation of 10 months
Sunday, September 30, 2012 at 9:03am by Ty

Question
The scores on a test are normally distributed with a mean of 140 and a standard deviation of 28, what is the score that is one standard deviation above the mean?
Friday, December 9, 2011 at 10:47am by Ray

statistics probability
The scores on a test are normally distributed with a mean of 140 and a standard deviation of 28, what is the score that is one standard deviation above the mean?
Sunday, November 14, 2010 at 4:06am by Ray

calculus
From f(x) you see that 500 is the mean and 50 the standard deviation. You can write the interval 450-550 as: 500 +/- 50 = mean +/- standard deviation So, what's the probability a normally distributed variable to be within one standard deviation of the mean?
Monday, June 4, 2012 at 4:22am by Count Iblis

Analytical Skills
If your score on a statistics exam was 76 and the professor gave you the distribution for the exam score for your class, you could find your percentile to understand where you stand in comparison to your fellow students. Assume that the distribution for exam scores is normally...
Thursday, October 6, 2011 at 6:28am by Jojo

statistics
Can you please tell me how to solve for the following? Pedro took an exam in a class in which the mean was 64 with a standard deviation of 6. If his z score was +3, what was his exam score? A students commute to school is normally distributed with a mean of 31 min and a ...
Sunday, July 28, 2013 at 11:37am by Sandra

Statistics
find the 90% confidence interval for the variance and standard deviation of the ages of seniors at Oak Park College if a sample of 24 students has a standard deviation of 2.3 years. Assume the variable is normally distributed. Can someone explain the steps to solve this? ...
Tuesday, October 26, 2010 at 9:46am by Diandra

Statistics
Are these statements true or false? 1. The sample mean, the sample proportion and the sample standard deviation are all unbiased estimators of the corresponding population parameters. 2. If the population is normally distributed with known variance then the sample mean may not...
Friday, November 5, 2010 at 5:03pm by help

Math
Random variables X and Y are both normally distributed with mean 100 and standard deviation 4. It is known that random variable X+Y is also a normal distribution. a. What is the mean of X+Y? b. What is the standard deviation of X+Y? I see that the mean is 200 but I don't know ...
Tuesday, November 15, 2011 at 12:00am by Rob

Statistics
Given that x is a normally distributed random variable with a mean of 28 and a standard deviation of 7, find the following probability: P(x<28) I understand that the means is 28 and the standard deviation is 7. However what I don't understand is how to get the value of x. ...
Tuesday, October 9, 2012 at 11:48am by Anonymous

college
Assume that the life expectancy of U.S. males is normally distributed with a mean of 80 years and a standard deviation of 4 years. What is the probability that a randomly selected male will live more than 85 years?
Thursday, April 29, 2010 at 10:06pm by Brittney

Statisitcs
The mean height of fully grown birch trees are 18 feet with a standard deviation of 1.2 feet, normally distributed. Random samples of size 9 are drawn from this population and the mean of each sample is determined. Find that mean and the standard error of the mean, and the ...
Wednesday, November 14, 2012 at 4:51pm by D

adult education
The lifetimes of lightbulbs of a particular type are normally distributed with a mean of 290 hours and a standard deviation of 6 hours. What percentage of the bulbs have lifetimes that lie within 1 standard deviation to either side of the mean?
Saturday, May 23, 2009 at 4:57pm by sally

Statistics
An electrical firm which manufactures a certain type of bulb wants to estimate its mean life. Assuming that the life of the light bulb is normally distributed and that the standard deviation is known to be 40 hours, how many bulbs should be tested so that we can be 90 percent ...
Friday, November 16, 2012 at 11:35am by Blerp

Word Problem
A math teacher gives two different tests to measure students' aptitude for math. Scores on the first test are normally distributed with a mean of 25 and a standard deviation of 4.6. Scores on the second test are normally distributed with a mean of 68 and a standard deviation ...
Sunday, March 7, 2010 at 9:09pm by Lyndse

statistics
Section 5.3: Normal Distributions: Finding Values Answer the questions about the specified normal distribution. Q1: The lifetime of ZZZ batteries are normally distributed with a mean of 265 hours and a standard deviation of 10 hours. Find the number of hours that represent ...
Sunday, March 28, 2010 at 9:35am by looking for someone to varify my work please

statistics
Assume that a population is normally distributed with a mean of 100 and a standard deviation of 15.
Monday, September 26, 2011 at 10:30am by michelle

statistics
The life span of the battery pack is known to be Normally distributed with a mean of 250 hours and a standard deviation of 20 hours. How to find the percentage of the battery packs lasting more than 250 hrs.
Sunday, May 6, 2012 at 4:31pm by noe

Finite Math
If the life in years, of a television set is normally distributed with a mean of 46 years and a standard deviation of 4 years, what should be the guarantee period if the company wants less than 3% of the television sets to fail while under warranty?
Saturday, February 13, 2010 at 11:20am by Maria

Stats
Suppose the time it takes for a purchasing agent to complete an online ordering process is normally distributed with a mean of 8 minutes and a standard deviation of 2 minutes. Suppose a random sample of 25 ordering processes is selected. The standard deviation of the sampling ...
Sunday, November 13, 2011 at 4:54pm by Jerry

statistics
It is well known that the heights of individual American men are normally distributed with mean 70 inches and standard deviation 2.8 inches. The Central Limit Theorem states that if n men are randomly chosen, then their average height will also be normally distributed with ...
Sunday, February 13, 2011 at 1:33pm by LISA

statistics
Cholesterol levels of adult males are approximately normally distributed with a mean of mg/dL and a listed standard deviation of . Some researchers claim that the standard deviation of cholesterol levels of adult males is less than . Suppose that we want to carry out a ...
Saturday, February 27, 2010 at 8:02pm by anaya

college math
Math homework please help!! 2. Suppose that peoples weights are normally distributed, with mean 175 pounds and a standard deviation of 6 pounds. Round to the nearest hundredth of a percent a. What percent of the population would weigh between 165 and 170 pounds? b. What ...
Tuesday, November 5, 2013 at 5:37pm by lynda

statistics
The most common intelligence quotient (IQ) scale is normally distributed with mean 100 and standard deviation 15. What score would put a child 3 standard deviations above the mean
Monday, September 3, 2012 at 6:52pm by Gee

statistics
The most common intelligence quotient (IQ) scale is normally distributed with mean 100 and standard deviation 15. What score would put a child 3 standard deviations above the mean
Monday, September 3, 2012 at 7:00pm by Gee

statistics
An investment broker reports that the yearly returns on common stocks are approximately normally distributed with a mean return of 12.4 percent and a standard deviation of 20.6 percent. On the other hand, the firm reports that the yearly returns on tax-free municipal bonds are...
Sunday, February 19, 2012 at 11:15pm by Anonymous

statistics
if the mean of a normally distributed set of data is 100 and the standard deviation is 10, a z score of 2 corresponds to raw value of?
Tuesday, November 2, 2010 at 11:02pm by g

Statistics
X is normally distributed with a mean of 250 and a standard deviation of 40. What value of X does only the top 15% exceed?
Friday, September 16, 2011 at 11:06pm by Joi

statistics
Assuming that the data are normally distributed with a mean of 45 and a standard deviation of 3.25, what is the z-score for a value of 40?
Thursday, October 20, 2011 at 2:08pm by Dean

finite math
kris scored 630 points on a particular section of a CPA exam for which the score were normally distributed with a mean of 600 points and a standard deviation of 75 points. At a differenttime, kerry scored 540 points on the same section, for which scores were normally ...
Thursday, April 14, 2011 at 2:46pm by margie

sample size/ standard deviations
How do we compute sample size fluctuations? Suppose we have a population of 16000 and a sample size of 30, and the number of samples 1000, what will be the impact on population mean and standard deviation when the population is normally distributed? When the population is ...
Thursday, December 1, 2011 at 10:15am by ut

math
kris scored 630 points on a particular section of a CPA exam for which the score were normally distributed with a mean of 600 points and a standard deviation of 75 points. At a differenttime, kerry scored 540 points on the same section, for which scores were normally ...
Tuesday, April 12, 2011 at 1:57pm by kaleb

math
kris scored 630 points on a particular section of a CPA exam for which the score were normally distributed with a mean of 600 points and a standard deviation of 75 points. At a differenttime, kerry scored 540 points on the same section, for which scores were normally ...
Wednesday, April 13, 2011 at 9:45am by shirley

Statistics
In a survey, the guess at the mean age for the class had a mean of 21.9 and a standard deviation of 3.03. Given that Normally distributed populations have a first quartile of Z=-0.67 and a third quartile of Z=.67, what does this suggest about whether or not these guesses are ...
Thursday, July 14, 2011 at 3:30pm by david

statistics
the dean of admissions in a large university has determined that the scores of the freshman class in a mathematics test are normally distributed with a mean of 86 and a standard deviation of 11. A sample of 50 students is selected at random from the entire freshman class. ...
Monday, March 26, 2012 at 7:56pm by Pat

statistics
The numbers of hours of life of a torch battery is normally distributed with a mean of 150 hours and standard deviation of 12 hours. In a quality control test, two batteries are chosen at random from a batch. If both batteries have a life less than 120 hours, the batch is ...
Wednesday, January 26, 2011 at 10:04am by Anonymous

statistics
Suppose scores on the mathematics section of the SAT follow a normal distribution with mean 540 and standard deviation 120. ACT math scores are normally distributed with a mean of 18 and a standard deviation of 8. What score on the ACT is equivalent to a score of 750 on the SAT
Sunday, September 15, 2013 at 11:07pm by Anonymous

statistics
the random variable x is normally distributed with a mean of 75 and a standard deviation of 15.0. For this distribution, what is the twenty-third percentile?
Friday, August 20, 2010 at 12:35am by marie

statistics
Suppose that is normally distributed with mean 90 and standard deviation 12. What value of does only the top 20% exceed?
Monday, September 19, 2011 at 5:37pm by sarah

statistics
A population is normally distributed with a man of 100 and a standard deviation of 15. is it unusual for themean of a sample of 3 to be 115 or more? Why or why not?
Monday, January 30, 2012 at 5:39pm by Donna

ivy tech
Assuming that the data are normally distributed with a mean of 45 and a standard deviation of 3.25, what is the z-score for a value of 40?
Thursday, August 30, 2012 at 12:43pm by ann

stats
if x is a normally distributed random variable with amean of 8.00 if the proability for x is less than 9.54 is 0.67, then find the standard deviation of x
Sunday, October 21, 2012 at 9:35am by tamara

statistics
Scores on an English test are Normally distributed with a mean of 78% and a standard deviation of 4.5%. Find the Value of the first quartile.
Monday, December 3, 2012 at 9:51pm by ray

statistics
Cholesterol levels of adult males are approximately normally distributed with a mean of mg/dL and a listed standard deviation of . Some researchers claim that the standard deviation of cholesterol levels of adult males is less than . Suppose that we want to carry out a ...
Saturday, February 27, 2010 at 8:05pm by anaya

Statistics
The time it takes for climbers to reach the highest point of a mountain is normally distributed with a standard deviation of 0.75 hours. If a sample of 35 people is drawn randomly from the population, what would be the standard error of the mean of the sample
Sunday, June 2, 2013 at 5:11pm by Quan

Statistics
The time it takes for climbers to reach the highest point of a mountain is normally distributed with a standard deviation of 0.75 hours. If a sample of 35 people is drawn randomly from the population, what would be the standard error of the mean of the sample
Sunday, June 2, 2013 at 11:25pm by Quan

probability and statistics
An electrical firm manufactures light bulbs that have a usuable life that is normally distributed with a mean of 1000 hours and a standard deviation of 80 hours. Find the probability that a package of 4 bulbs would last at least 4400 hours.
Sunday, April 29, 2012 at 7:57pm by Kim

statistics
IQ scores are normally distributed with a mean of 105 and a standard deviation of 18. Assume that many samples of size n are taken form a large population of people and the mean IQ score is computed for each sample. If the sample size is n=64, find the mean and standard ...
Thursday, September 13, 2012 at 3:51pm by kimberly

statistics
skating speeds are normally distributed with a mean of 60 and a standard deviation of 10. Determine the speed that separates the top 6% from the rest.
Wednesday, November 13, 2013 at 10:08am by peter

statistics
the life expectancy of lung cancer patient treated with a new drug is normally distributed with a mean of 4 years and a standard deviation of 10 months what is the probability that a randomly selected lung cancer patient will last more than 5 years
Sunday, March 28, 2010 at 11:08am by yolanda

statistics
Suppose scores on the mathematics section of the SAT follow a normal distribution with mean 540 and standard deviation 120. ACT math scores are normally distributed with a mean of 18 and a standard deviation of 8. What score on the ACT is equivalent to a score of 750 on the ...
Monday, September 16, 2013 at 1:46pm by Anonymous

stat
for randomly selected adults, IQ scores are normally distributed with a standard deviation of 15. the scores of 14 randomly selected college students are listed below. use a 0.10 significance level to test the claim that the standard deviation of IQ scores of college students ...
Monday, May 14, 2012 at 9:33am by carl

statistics
How do we compute sample size fluctuations? Suppose we have a population of 16000 and a sample size of 30, and the number of samples 1000, what will be the impact on population mean and standard deviation when the population is normally distributed? When the population is ...
Thursday, December 1, 2011 at 8:19am by Nasir

stats
The life of tires manufactured by Omega Tires Inc is believed to be normally distributed with a mean of 110,000 km and a standard deviation of 5,000 km. A random sample of 200 tires is tested . What is the problability of the mean life of this sample being between 109,000 and ...
Tuesday, October 9, 2012 at 10:46am by Carlos

statistics
Suppose that the population standard deviation () for a normally distributed standardized achievement test (ACT) is 6. What would the standard error of the sample mean (xbar) be if we were to draw a random sample of 36 test scores?
Tuesday, October 4, 2011 at 3:53pm by Anonymous

stats
Assume that aset of test scores is normally distributed with a mean of 100 and a standard deviation of 20 use the 68-95-99?
Sunday, July 4, 2010 at 3:25pm by Anonymous

Math
The scores on a standardized test are normally distributed with the mean of 750 and standard deviation 70. Find the probability that a score is more than 890.
Tuesday, May 21, 2013 at 2:50pm by Denise

statistics
A psychologist studied self esteem scores and found the sample data set to be normally distributed with a mean of 50 and a standard deviation of 5?
Saturday, January 25, 2014 at 7:36pm by Stephanie

math
on a mathematics test in high school, scores are normally distributed with a mean of 77 and a standard deviation of 16.8. A students is randomly selected.
Saturday, February 1, 2014 at 8:47pm by Anonymous

Stats
A simple random sample will be obtained from a normally distributed population. Find the minimum sample size needed to be 99% confident that the sample standard deviation s is within 5% of the standard deviation. Is such a sample size practical in most cases? The minimum ...
Monday, November 28, 2011 at 9:50pm by Lindsey

Statistics
IQ score are normally distributed with a mean of 95 and a standard deviation of 17. If the sample size is n=36 find the mean and standard distribution of sample mean
Sunday, April 7, 2013 at 2:47pm by Megan

statistik
can you show me the calculation ;) The life expectancy of computer terminals is normally distributed with a mean of 4 years and standard deviation for 10 months. a. What is the probability that a randomly selected terminal will last more than 5 years? b. What percentage of ...
Sunday, December 2, 2012 at 6:31am by mira

Statisitics:Standard Deviation of Population and o
The weight x of all female German Shepherds is approximately normally distributed with population mean u=64 pounds and population standard deviation of o=8 pounds. a)What is the probability that a randomly selected female german shepherd weighs more than 75 pounds? p(x>75)?)
Tuesday, September 11, 2007 at 4:25pm by Robin

statistics
Let x be a continuous random variable that is normally distributed with a mean of 65 and a standard deviation of 15. Find the probability that x assumes a value less than 44.
Monday, April 18, 2011 at 9:01pm by Katie

statistics
Let x be a continuous random variable that is normally distributed with a mean of 65 and a standard deviation of 15. Find the probability that x assumes a value less than 45.
Monday, April 18, 2011 at 9:02pm by Katie

statistics
In a population of normally distributed aptitude scores of 1000 academy students with mean 70 and Standard deviation 10, how many score above 95?
Tuesday, May 10, 2011 at 10:21pm by Lisa

BUSINESS STATISTICS
The random variable x is normally distributed with mean =1,000 and standard deviation =100. Sketch and find each of the following probabilities: P(x<1,035)
Sunday, October 16, 2011 at 10:01pm by Shirley

BUSINESS STATISTICS
The random variable x is normally distributed with mean =1,000 and standard deviation =100. Sketch and find each of the following probabilities: P(x<1,035)
Tuesday, October 18, 2011 at 6:20am by Shirley

statistics
Let x be a continuous random variable that is normally distributed with a mean of 65 and a standard deviation of 15. Find the probability that x assumes a value less than 44.
Wednesday, October 31, 2012 at 10:05pm by Anonymous

Statistics
I am so lost on this statistics question would someone help me figure out how to answer it? A random variable X is normally distributed with the mean and standard deviation 1.6. What is the proportion of the data values that lies within 1.6 standard deviations from the ...
Tuesday, November 27, 2012 at 11:55am by Layney

Algebra
For questions 1 and 2 use the following info. The numbers are in this order: 456,306,160,363,376,935,54,349 1)Find the mean, median ,mode, and standard deviation of the data. Round to the nearest hundredth, if nessesary. mean= added all numbers and divided by 8 and got 384.9 ...
Wednesday, March 5, 2008 at 6:36pm by Jon

statistics
Suppose it is known that the average score of all high school seniors taking a national test of basic skills is 420. These scores are normally distributed with a standard deviation of 80. A school gives the test to a sample of 144 seniors. Identify the following ...
Tuesday, October 2, 2012 at 7:31pm by nana

statistics
SAT scores are normally distributed with a mean of 1518 and a standard deviation of 325. What scores correspond to P20 and P65?
Saturday, November 27, 2010 at 2:20pm by Jacob

statistics
The mean of a normally distributed data set is 226.2. The data item, 230, has a z-score of 0.2. Find the standard deviation.
Wednesday, January 16, 2013 at 4:36pm by Anonymous

statistics
CALCULATE THE PERCENTAGE OF CASES THAT FALL BETWEEN THE SCORES 120 AND 110 ON A NORMALLY DISTRIBUTED iq TEST WITH A MEAN OF 100 AND A STANDARD DEVIATION OF 10
Tuesday, November 30, 2010 at 8:02pm by ROXIE

statistics
Let X be a continuous random variable that is normally distributed with mean, = 15 and standard deviation, σ = 2.8, find a value xo that represents the 80th percentile of the distribution.
Thursday, March 3, 2011 at 5:42pm by Jessie

statistics
The mean (μ) of the scale is 98 and the standard deviation (σ) is 13. Assuming that the scores are normally distributed, what is the PROBABILITY that a score falls below 88?
Tuesday, February 28, 2012 at 9:12pm by Anonymous

algebra
Diameter of an electric cable is normally distributed with a mean f 0.8 with a standard deviation of 0.01. What is the probability that the diameter will exceed 0.83?
Tuesday, November 29, 2011 at 1:27am by debra rees

statistics
A set of data is normally distributed with a mean of 98 and a standard deviation of 15. What is the probability that the value from the data is less than 88 ?
Thursday, December 1, 2011 at 9:40pm by Anonymous

Math
The mean of a set of normally distributed data is 550 and the standard deviation is 35. What percent of the data is between 515 and 585?
Tuesday, May 8, 2012 at 6:50am by nichole

Statistics
The yearly returns of a stock are normally distributed with a mean of 5.1% and standard deviation of 2.7%. Find the probability of a yearly return being greater than 6%.
Wednesday, April 24, 2013 at 6:38am by Rem

statistics
Given a population of scores is normally distributed with mu of 110 and a standard deviation of 8 the percentage of scores that are below a score of 99?
Thursday, June 6, 2013 at 10:40pm by Debra

Stats
The lifetime of a particular type of battery is normally distributed with a mean of 1100 days and a standard deviation of 80 days. The manufacturer randomly selects 400 batteries of this type and ships them to a departmental store. (a) What is the mean and standard deviation ...
Thursday, June 5, 2008 at 10:18pm by Dherain

topics of math
A population is normally distributed with mean 43.7 and standard deviation 5.2. Find the following probability. (Round your answer to four decimal places.) p( x > 55.0 )
Wednesday, April 6, 2011 at 8:06pm by Hannah

statistics
cost of producing is 50 cents each and they sell for 1.25 each. demand for programs at each game is normally distributed with a mean of 2500 and standard deviation if 200. how many shouild be prodcued
Saturday, November 19, 2011 at 9:22am by Anonymous

math
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours?
Monday, April 2, 2012 at 6:10pm by Bridget

statistics
If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours?
Sunday, May 26, 2013 at 2:49pm by madonna

Statistics
IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15. Find the x- score that corresponds to a z-score of 2.33.
Sunday, March 13, 2011 at 5:47pm by chalulu

statistics
A population is normally distributed with a mean of 40 and a standard deviation of 6. For samples of size 10, what is the probability that the sample mean will be more than 42?
Thursday, March 17, 2011 at 8:58am by anne

Statistics
jenny is 5'10" tall. the heights of the girls in the school are approximately normally distributed with a mean of 5'5" and a standard deviation of 2.6". What is the percentile of jenny's height?
Thursday, May 5, 2011 at 1:53am by Confused

statistics
Scores on a recent national statistics exam were normally distributed with a mean of 80 and a standard deviation of 6. What is the percentile rank of a score of 89?
Thursday, July 7, 2011 at 5:29pm by Anonymous

Math
Assume that a population is normally distributed with a mean of 100 and a standard deviation of 15. Would it be unusual for the mean of a sample of 3 to be 115 or more? Why or why not?
Monday, October 3, 2011 at 1:50am by Katty

statistics
Assume that a population is normally distributed with a mean of 100 and a standard deviation of 15. Would it be unusual for the mean of a sample of 3 to be 115 or more? Why or why not?
Monday, October 3, 2011 at 6:12pm by Jenifer

statistics
Assume that a population is normally distributed with a mean of 100 and a standard deviation of 15. Would it be unusual for the mean of a sample of 3 to be115 or more?
Sunday, November 27, 2011 at 8:53pm by Mile

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