Friday

September 19, 2014

September 19, 2014

Number of results: 20,589

**Math**

Can someone explain what to do for the following question. What percentage of a normal distribution is greater than the mean? Give your answer correct to the nearest percent. What formula is used? Because I have to find also 1 standard deviation of the mean and what percentage...
*May 22, 2013 by Sue*

**statistics**

I.use the chebyshev's theorem to find out what percentage of the values will fall between 201 and 257 for a data set with a mean of 229 and standard deviation of 14. II. use the emperical rule to find out two values 68% of the data will fall between for a data set with a mean ...
*October 11, 2010 by mary*

**statistics**

For a population with a mean of 30 and standard deviation of 6, describe the sampling distribution of the means for samples of N=9.
*November 3, 2009 by Ashley*

**statistics**

Given a data set with the mean = 44 and the standard deviation = 15, what is the value of the Third Quartile?
*September 10, 2010 by angie*

**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*

**statistics**

what percentage of students studied between 30 and 40 hours? Range 10-50, Mean- 35, standard deviation-5.
*October 14, 2010 by kim*

**statistics**

with a mean of 62 and standard deviation of 12, how would you find a proportion greater than 80 and draw it on a curve?
*December 2, 2010 by kaitlyn*

**Statistics**

How large a smaple from a N(80,20) population is needed so that the sampling distribution of the mean has a standard deviation of 1?
*January 4, 2011 by Alana*

**Statistics**

How large a sample from N(80,20) population is needed so that the sampling distribution of the mean has a standard deviation of 1?
*January 4, 2011 by Casey*

**statistics**

in a distribution of scores with a mean of 1500 and a standard deviation of 250, what is the 95th percentile?
*February 26, 2011 by Ruben*

**statistics**

Make up 20 hypothetical scores. Determine their mean, median, mode, and standard deviation.
*June 24, 2011 by Janet*

**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?
*October 20, 2011 by Dean*

**statistics**

we have a normal distribution with mean 76 and standard deviation 6.4, find the percent between 69.6 & 76?
*November 8, 2011 by laura*

**statistics**

A random sample of size 36 is taken from a population with mean 50 and standard deviation 5. Find P( < 51.5).
*July 6, 2012 by dave*

**Criminology Statistics**

A given distribution has a mean of 60. A score of 75 had a corresponding z of +2.00. The standard deviation is
*March 1, 2013 by Mariah*

**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**

population with a mean of 110 and a standard deviation of 6, what is the likelihood of a score of 100 or lower
*July 4, 2013 by carole*

**statistics**

You have an observation of 55, a population mean of 48, and a standard deviation of 1.85. Therefore, the z-score would be:
*February 10, 2014 by Anonymous*

**statistics**

A specific study found that the average number of doctor visits per year for people over 55 is 8 with a standard deviation of 2. Assume that the variable is normally distributed. 1. Identify the population mean. 2. Identify the population standard deviation. 3. Suppose a ...
*April 15, 2013 by Cam*

**Math - Standard Deviation**

A General Electric soft white 3-way bulb has an average life of 1200 hours with a standard deviation of 50 hours. Find the probability that the life of one of these bulbs will be between 1150 and 1300 hours. You need to change the times to Z-scores â€” scores given in terms of...
*July 22, 2005 by GetYourLeash*

**statistics**

for a distribution standard deviation=10.If every item is increased by 2 then what will new standard deviation?
*September 27, 2011 by Anonymous*

**statistics**

for a distribution standard deviation=10.If every item is increased by 2 then what will new standard deviation?
*September 27, 2011 by ria*

**Math- Statistics**

A random sample of size 36 is to be selected from a population that has a mean μ = 50 and a standard deviation σ of 10. * a. This sample of 36 has a mean value of , which belongs to a sampling distribution. Find the shape of this sampling distribution. * b. Find the ...
*February 8, 2011 by Tammy*

**statistics**

population mean=42.6 standard deviation=12 n=16 M=34.4. Is this mean a reasonable outcome for a sample of n=16, or is this sample mean very different from what would usually be expected? I obtained a z -score of -2.73. Thus, that would make the sample mean a reasonless outcome...
*May 29, 2008 by Lindy*

**Statistics**

Thirty random students took a calc test. If the sample mean was 90 & the standard deviation was 13.9, construct a 99% confidence interval for the mean score of all students. Is the answer 83.03 to 96.97??
*September 14, 2008 by Shannon*

**Statistics**

Suppose that a sample of size 58 is drawn from a population with mean 23 and standard deviation 80. Find the value of , the mean of the distribution of sample means. Wrtie only a number as your answer.
*June 20, 2013 by Anonymous*

**math**

find the standard deviation for the following: 8,5, 12, 8, 9, 15, 21, 16, 3. There is a formula but our teacher wants us to do it a specific way. For example, 47, 41, 32, 53, 57. First you find the mean, which is 46 and then subtract it with each number in the set so you get 1...
*December 8, 2013 by sarah*

**statistics**

An IQ is designed so that the mean is 100 and the standard deviation is 23 for the population of Normal adults, find the sample size necessary to estimate the mean IQ score of statistics students Such that it can be said with 90% confidence that the sample mean is within 5 IQ ...
*May 19, 2014 by joe*

**statistics**

A student scores 600 on a SAT test. If the population mean of the test scores is 510 and the population standard deviation is 106 point, what is the student’s deviation from the mean?
*December 8, 2011 by violet*

**Math**

On a standardized test, Phyllis scored 84, exactly one standard deviation about the mean. If the standard deviation for the test is 6, what is the mean score for the test?
*October 22, 2012 by Tanyetta*

**statistics**

a research participant has her brain scanned while listening to music and solving math problems, and the brain area of interest has a percent signal change of 58. From many previous studies with this same math-problems procedure (but not listening to music), it is known that ...
*January 13, 2012 by Anonymous*

**Statistics**

The law of large numbers tells us what happens in the long run. Like many games of chance, the numbers racket has outcomes so variable - one three-digit number wins $600 and all others win nothing - that gamblers never reach "the long run." Even after many bets, their average ...
*February 25, 2014 by Ray*

**Statistics**

The law of large numbers tells us what happens in the long run. Like many games of chance, the numbers racket has outcomes so variable - one three-digit number wins $600 and all others win nothing - that gamblers never reach "the long run." Even after many bets, their average ...
*February 25, 2014 by Ray*

**Statistics**

The law of large numbers tells us what happens in the long run. Like many games of chance, the numbers racket has outcomes so variable - one three-digit number wins $600 and all others win nothing - that gamblers never reach "the long run." Even after many bets, their average ...
*February 25, 2014 by PLEASE HELP!!!!!!!!!*

**math**

A district mathematics test for all third graders had a normal distribution with a mean of 74 and a standard deviation of 11. What percentage of the third graders tested scored with +1 and -1 standard deviation of the mean?
*July 5, 2013 by Anonymous*

**statistics**

it is stated that the standard deviation sample of the is 7.6 (n = 26). Test the claim to a significance level of 0.10 that the population standard deviation was greater than 7.0. Round all answers to 3 decimal places.
*July 28, 2012 by geety*

**statistics**

it is stated that the standard deviation sample of the is 7.6 (n = 26). Test the claim to a significance level of 0.10 that the population standard deviation was greater than 7.0. Round all answers to 3 decimal places.
*July 28, 2012 by geety*

**QNT/351**

Describe a business situation, other than what has already been selected by fellow students or selected from the team assignment, where mean and standard deviation can be used in decision making. Describe how calculation of mean and standard deviation can help in making a ...
*November 26, 2013 by Karen*

**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?
*May 23, 2009 by sally*

**Math**

if a test given to 100 people have a mean of 3.5 and a standard deviation is .5, what is the standard deviation of someone who scores 1.5>
*April 8, 2009 by Debra*

**math**

if a test given to 100 people have a mean of 3.5 and a standard deviation is .5, what is the standard deviation of someone who scores 1.5?
*April 8, 2009 by Debra*

**Math**

Would you rather take an exam that typically has an mean of 80 with a standard deviation of 3 or an exam with a mean of 80 with a standard deviation of 15? why?
*December 2, 2010 by Rena *

**Math**

Would you rather take an exam that typically has an mean of 80 with a standard deviation of 3 or an exam with a mean of 80 with a standard deviation of 15? why?
*December 3, 2010 by Rena *

**Statistics**

A normally distributed population has a mean of 40 and a standard deviation of 12. What does the central limit theorem say about the sampling distribution of the mean if samples of size 100 are drawn from this population.
*July 17, 2012 by Christie*

**statistics**

The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures students' study habits and attitudes toward school. Scores range from 0 to 200. The mean score for college students is about 115.8, and the standard deviation is about 32.9. A teacher ...
*March 1, 2011 by Yesenia*

**Data and statistics**

If a student had a z score of 2.5 for IQ, whar is his actual IQ? The IQ mean is 100, and standard deviation is 15.
*July 22, 2010 by Beverly*

**business statistics**

solv the following a)mean b)mode c)median d)standard deviation observation Frequency 5 14 10 22 15 47 20 17
*November 29, 2010 by Anonymous*

**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?
*September 16, 2011 by Joi*

**statistics**

Suppose that is normally distributed with mean 90 and standard deviation 12. What value of does only the top 20% exceed?
*September 19, 2011 by sarah *

**statistics**

For a distribution in which the mean is 100 and the standard deviation is 12, find the following: the percentile of a score of 106.
*September 30, 2011 by Jennifer*

**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? (Points : 6) 1.54 2.38 -1.36 -1.54
*October 19, 2011 by Anonymous*

**statistics**

Given a normally distributed population of values with a mean of 76 and a standard deviation of 10 what is the probability that a value is 71 and 82
*September 9, 2014 by bono*

**econ**

12) Suppose you know that the standard deviation of a variable is 10, and you have 100 observations, the standard deviation of the mean is
*November 27, 2011 by Alyson*

**Statistics/ is this how I do it.**

Find the range and the standard deviation (correct to two decimal places). 83,96,100,100,103 find the range and standard deviation Do I that 5 numbers add that divide by 5 for the range I am not sure how to do standard deviation. Thank you
*May 31, 2014 by Mary Ann *

**statistics**

Prep Courses? Scores for men (nationwide) on the verbal portion of the SAT test are normally distributed with a mean of 509 and a standard deviation of 112. Randomly selected men are given the Columbia review course before taking the SAT test. After the course, a sample of 49 ...
*June 28, 2010 by STatistic*

**Business Statistics**

1. Suppose that the mean of the annual return for common stocks from 1950 to 2012 was 9.4%, and the standard deviation of the annual return was 17.5%. Suppose also that during the same 62-year time span, the mean of the annual return for long-term government bonds was 4.6%, ...
*March 6, 2013 by Michelle*

**stats please help ASAP!!!**

A. The GPAs of all 5540 students enrolled at a University have an approximately normal distribution with a mean of 3.02 and a standard deviation of 0.29. Let x be the mean GPA of a random sample of 48 students selected from this University. Find the mean and standard deviation...
*May 17, 2013 by DON*

**Statistics**

The weights of the fish in a certain lake are normally distributed with a mean of 11 lb and a standard deviation of 6. If 4 fish are randomly selected, what is the probability that the mean weight will be between 8.6 and 14.6 lb? A) 0.0968 B) 0.4032 C) 0.3270 D) 0.6730
*November 25, 2010 by Sarah*

**statistics**

A researcher randomly selects 37 subjects and administers an attitude test regarding a product. Their mean is 22 and their standard deviation is 2.4. Construct the 90% confidence interval for the mean score of all such subjects
*February 23, 2011 by mandy*

**statistics**

A food manufacturer samples 7 bags of pretzels off the assembly line and weighs their contents. If the sample mean is 14.2 oz and the sample standard deviation is 0.60 oz., find the 95% confidence interval of the true mean.
*March 16, 2014 by Anonymous*

**Statistics**

Assume that the cure rate for a certain drug is 20% and that 15 patients are tested with this drug. Find the following: a) Mean b) Standard Deviation c) P (exactly 4 cures) d) P (exactly 4 cures) A snack company distributes chips in bags labeled 6 ounces. The local Bureau of ...
*December 11, 2006 by Mary*

**statistics**

The population standard deviation (σ) for a standardized achievement test that is normally distributed is 8. a.) Calculate the standard error of the mean if you draw a random sample of 50 test scores. Show your work for full credit . . . b.) Your sample mean is ...
*February 21, 2012 by PK*

**Statistics**

Lead (Pb) concentrations were measured in waterfowl eggshell samples from two locations. In n1 = 41 samples from a location downstream from a paper mill, the mean Pb concentration was 1 x = 0.13 ppm with a standard deviation of s1 = 0.04 ppm. In n2 = 31 samples from a location...
*November 7, 2012 by Erik*

**Statistics**

Lead (Pb) concentrations were measured in waterfowl eggshell samples from two locations. In n1 = 41 samples from a location downstream from a paper mill, the mean Pb concentration was 1 x = 0.13 ppm with a standard deviation of s1 = 0.04 ppm. In n2 = 31 samples from a location...
*November 7, 2012 by Erik*

**Statistics**

Can any one help me with this? ThermoStar has been producing residential thermostats for over 50 years. Looking over the past 20 quarters (5 years) of the different product lines, the general manager has been trying to get a handle on sales, costs, and production, and has ...
*August 20, 2009 by Trisha*

**statistics**

The human resources department of an engineering company gives IQ tests to a randomly selected group of new hires every year. They claimed that the mean IQ score of new hires, , from this year is greater than or equal to the mean IQ score of new hires, , from last year. This ...
*August 3, 2014 by Brittany*

**statistics**

A bus company official wanted to estimate the mean time for the trip between two cities. A random sample of such trips gave a mean of 152 minutes and a standard deviation of 12 minutes. Construct a 98% confidence interval for the population mean time.
*July 9, 2011 by John*

**Statistics**

The distribution of heights of adult American men is approximately normal with a mean of 68 inches and a standard deviation of 2 inches. What percent of mean are at least 72 inches tall?
*July 4, 2013 by Anonymous*

**statistics**

at a bank, account balances are nomrally distribued with a mean of $637.52 and standard deviation of $623.16. What is the probability that a simple randon same of 400 accounts has mean that exceeds $1650.00? show me steps and calculations i urgently need help
*January 23, 2008 by son*

**stastics**

A recent article in a computer magazine suggested that the mean time to fully learn a new software program is 40 hours. A sample of 100 first-time users of a new statistics program revealed the mean time to learn it was 39 hours with the standard deviation of 8 hours. At the 0...
*June 5, 2010 by slayer*

**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...
*February 19, 2012 by Anonymous*

**Statistics**

What measurement forms normal distribution? Would it be the mean and variance? (avg. and standard deviation) Could you help me please
*October 15, 2008 by Lexi*

**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?
*August 20, 2010 by marie*

**statistics**

Scores on an english test are normally distributed with a mean of 33.6 and a standard deviation of 8.3. Find the 41st percentile?
*November 1, 2010 by English Test Scores*

**Statistics**

If the mean of a set of data is 20.00 and 12.20 has a z-score of -1.30, then the standard deviation must be: What formula would you use to determine this?
*April 7, 2011 by Belinda*

**Statistics**

What score in a distribution that has a mean of 500 and a standard deviation of 100, would identify the top 60% of scores?
*April 9, 2011 by Melissa*

**statistics**

For the following scores, find the (a) mean, (b) median, (c) sum of squared deviations, (d) variance, and (e) standard deviation 3.0, 3.4, 2.6, 3.3, 3.5, 3.2
*August 14, 2011 by Donna*

**statistics**

how do i calculate the SAT score that defines the bottom 3% of students with a mean of 500 and standard deviation of 100
*September 20, 2012 by Penny*

**Statistics**

19. George got 70% on an economics exam where the mean was 55% and the variance was 9. If a professor wishes to change the distribution of marks so that they have a mean of 70% and a standard deviation of 5, what will George’s new mark be? a) 95% b) 85% c) 90% d) Over 100% The...
*October 23, 2010 by Rhea *

**Statistics**

Suppose that two different tests A and B are to be given to a student chosen at random from a certain population. Suppose also that the mean score on test A is 85, and the standard deviation is 10; the mean score on test B is 90, and the standard deviation is 16; the scores on...
*February 16, 2011 by Charles*

**statistics**

The U.S. Dairy Industry wants to estimate the mean yearly milk consumption. A sample of 20 people reveals the mean yearly consumption to be 72 gallons with a standard deviation of 15 gallons. What is the 99% confidence interval for the population mean?
*November 4, 2012 by Jelian*

**statistics**

A university has 1000 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 of...
*October 20, 2013 by Anonymous*

**statistics**

A person scores 81 on a test of verbal ability and 6.4 on a test of quantitative ability. For the verbal ability test, the mean for people in general is 50 and the standard deviation is 20. For the quantitative ability test, the mean for people in general is 0 and the standard...
*April 16, 2009 by Mary*

**statistics**

A person scores 81 on a test of verbal ability and 6.4 on a test of quantitative ability. For the verbal ability test, the mean for people in general is 50 and the standard deviation is 20. For the quantitative ability test, the mean for people in general is 0 and the standard...
*June 29, 2009 by Gregory*

**Math/Statistics**

A statistics teacher believes that the final exam grade for her elementary stats class have a normal distribution with a mean of 82 and a standard deviation on 8. Find the score which separates the top 10% of the scores from the lowest 90% of the scores.
*August 11, 2013 by Sean*

**math30**

The Mean and the Standard Deviation Last year, golfers at Smith Ranch golf course had a mean score of 41 and a standard deviation of 2 on the first nine holes of the course, and a mean of 38 and a standard deviation of 1.8 on the last nine holes. One afternoon, Nathan scored ...
*February 13, 2013 by alejandro*

**statistics**

For normal population mean 60, standard deviation 15, after treatment is given to the member of sample , the sample mean is 65, and sample size is 25. is the sample mean sufficient to conclude that the treatment has significant effect? Give reason for decision?
*August 11, 2012 by Anonymous*

**math**

find the standard deviation for the following: 8,5, 12, 8, 9, 15, 21, 16, 3. There is a formula but our teacher wants us to do it a specific way. For example, 47, 41, 32, 53, 57. First you find the mean, which is 46 and then subtract it with each number in the set so you get 1...
*December 8, 2013 by sarah*

**statistics**

say that you have a distribution of exam scores with a mean of 57 and a standard deviation of 7. if a student in the class has a standard score equal to 2.429, what would their raw score on the exam be?
*December 2, 2012 by Dawn*

**Statistics**

Mrs. Marble gave her 5th grade class a math test. The scores reflect a relatively normal distribution. The mean score for the group was 80 with a standard deviation of 8. Based upon this information, answer the following questions: Bobby scored exactly two standard deviations ...
*January 27, 2013 by Susana*

**STATISTICS**

Can someone please tell me how to solve this problem? A buyer for a lumber company must determine wheter to buy a piece of land containing 50,000 trees. if 2000 tress are at least 48 feet tall she will purchase the land; otherwise she will not. the owner of the land reports ...
*April 20, 2007 by DEE-DEE*

**Statistics**

Through extensive research, Metlife Insurance claims that the mean footwell intrusions for Toyota Corrola and Toyota Rav4 are equal. Crash test at 40mph were performed at 7 randomly selected Toyota Corrola and 13 randomly Toyota Rav4s selected. The amount that the footwell ...
*April 4, 2012 by Lisa*

**statistics**

Assume that the mean hourly cost to operate a commercial airplane follows the normal distribution with a mean of $2,225 per hour and a standard deviation of $220. What is the operating cost for the lowest 5 percent of the airplanes?
*November 21, 2010 by Barbara*

**statistics**

A food snack manu. samples 15 bags of pretzels off the assembly line and weighed their contents. If the sample mean is 10.0 and the sample standard deviation is .15, find the 95% confidence interval estimate for the true mean.
*January 3, 2013 by Kelly*

**Stats**

a plumbing supplier's mean monthly demand for vinyl washers is 24212 with a standard deviation of 6053. The mean monthly demand for stem boilers is 6.8 with a standard deviation of 1.7. Comapre the dispersion of these distributions. Which demand pattern has more relative ...
*July 28, 2008 by Bill*

**math**

A plumbing supplier’s mean monthly demand for vinyl washers is 24,212 with a standard deviation of 6,053. The mean monthly demand for steam boilers is 6.8 with a standard deviation of 1.7. Compare the dispersion of these distributions. Which demand pattern has more relative ...
*July 12, 2010 by bebe*

**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?
*November 2, 2010 by g*

**Statistics**

Given a population with a normal distribution, a mean of 100, and a standard deviation of 1, what value has an area of .1234 to its right?
*December 9, 2010 by Ed*

**statistics**

a standardized test has a mean of 88 and a standard deviation of 12. What is the score at thr 90th percentile? Assume a normal distribution.
*February 8, 2011 by cw*

**Math (Statistics)**

I am to find the mean, variance, and standard deviation for the probability distribution. I don't even know where to start. Here is the problem x P(x) 0 0.19 1 0.32 2 0.28 3 0.21
*March 14, 2011 by Heather*

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