Monday

February 8, 2016
Number of results: 9,268

**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
*November 19, 2011 by Anonymous*

**statistics**

assume that adults have IQ scores that are normally distributed with a mean of 100 and a standard deviation of 20. find the probability that a randomly selected adult has an IQ less than 20.
*March 14, 2012 by samantha *

**statistics**

psychologist wants to interview subjects with IQ scores are normally distributed with mean of 100 and standard deviation of 15. find the score that separating the top of IQ frin the bottom 90%
*May 9, 2012 by joe*

**Statistics for Social Science**

A random sample of 80 students at a largae school shows an average grade of 72 in Algebra with a standard deviation of 4. Find the standar error.
*November 24, 2012 by Pearl*

**statistics**

sample size needed with a mean of 100,standard deviation of 20 for the the population of normal adults an iq range to fall between 2 iq points with 95% confidence interval
*December 1, 2012 by krissy*

**Statics**

A candy machine distributor collects the coins from 100 machines. The standard deviation is $3.25. With probability 98%, what is the maximum error about the true mean that will result?
*December 1, 2012 by Heather*

**Biostats **

If the average (xbar) on an assignment in a class was 82% with a standard deviation (s) of 4.8, what is the z-score for someone scoring 75% (round to the one hundredths place or two decimal places)?
*February 3, 2013 by brittany *

**statistics**

I need a estimate within $25, the true average of amount of postage a company spends each year. If I want to be 98% confident, how large a sample is necessary? The standard deviation is known to be $80
*March 29, 2013 by ann*

**Stats **

The high temperature X (in degrees Fahrenheit) on January days in Columbus, Ohio varies according to the Normal distribution with mean 21 and standard deviation 10. The value of P(X < 10) is
*March 29, 2014 by Tracy *

**statistics**

How large a sample should be selected to provide a 95% confidence interval with a margin of error of 10 (to the nearest whole number)? Assume that the population standard deviation is 40.
*April 21, 2014 by Vanessa*

**data analysis**

A survey of 1500 college students found that 675 stay on campus in a dorm. Find the mean and standard deviation of the proportion of the sample.
*May 20, 2014 by Anonymous*

**Math**

Scores on a marketing exam are known to be normally distribute with mean and standard deviation of 60 and 20, respectively. The syllabus suggests that the top 15% of the students will get an A in the course. What is the minimum score required to get an A?
*September 25, 2014 by Sam*

**statistics**

studies indicate that drinking water supplied by some old lead-lined city piping systems may contain harmful levels of lead. an important study of the Boston water supply system showed that the distribution of lead content readings for individual water specimens had a mean and...
*March 14, 2011 by dinhgde*

**chemistry**

This is super confusing complex brain killing A column packing for chromatography consists of a mixture of two types of particles. Assume that the particles in the batch being sampled are spherical with a radius of 0.5 mm. 36% of the particles appeared to be pink and are known...
*March 28, 2010 by Simon*

**Statitics**

25 periodicals have a mean of $180 and a standard deviation of $12. form a 95% confidence interval on the population mean.
*March 20, 2009 by Sally*

**STATISTICS**

Find the sample standard deviation s for the following sample data. Round your answer to the nearest hundredth. x: 23 20 11 33 27
*June 3, 2010 by Jake*

**Math**

Suppose the mean heights of a population are 72 inches with a standard deviation of 2 inches. What height (x) corresponds to the z value of 1
*May 14, 2011 by Phillip*

**math**

with a mean of 515 and a standard deviation of 135, what percentage score 110-515 using the 68-95-99.7 rule
*October 26, 2011 by Ron*

**Math**

Given the following frequency distribution, find the mean, variance, and standard deviation. Class Frequency 31-33 18 34-36 25
*November 10, 2011 by Jennifer*

**Math**

Given the following frequency distribution, find the mean, variance, and standard deviation. Class Frequency 31-33 18 34-36 25 37-39 22 40-42 9 43-45 20
*November 10, 2011 by Jennifer*

**statistics**

If scores are normally distributed with a mean of 3.06 and a standard deviation of 0.84, what percent of the scores is: (a) greater than 3.9? (b) less than 2.22? (c) between 2.22 and 3.9?
*November 28, 2011 by jennifer*

**statistics**

If scores are normally distributed with a mean of 3.06 and a standard deviation of 0.84, what percent of the scores is: (a) greater than 3.9? (b) less than 2.22? (c) between 2.22 and 3.9?
*November 28, 2011 by jennifer*

**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?
*November 29, 2011 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 ?
*December 1, 2011 by Anonymous*

**algebra**

A normal distribution has a mean of 98 and a standard deviation of 6. What is the probability that a randomly selected x-value from the distribution is at least 80?
*May 23, 2012 by jenny*

**statistics**

For a population with a mean of 250 and a standard deviation of 47, return each of the following z scores to raw scores on this variable. a. 0.54 b. -2.66 c. -1.0 d. 1.79
*September 3, 2012 by tammy*

**stat in psyc**

A normal distribution has µ = 80 and standard deviation = 10. What is the probability of randomly selecting a score greater than 90 from this distribution
*March 3, 2013 by shauna*

**Statistics**

For the following set of scores, fill in the cells. The mean is 70 and the standard deviation is 8. Raw score Z score 68.0 ? ? –1.6 82.0 ? ? 1.8 69.0 ? ? –0.5 85.0 ? ? 1.7 72.0 ?
*November 26, 2014 by KIM*

**math**

A normal distribution has a mean of 44 and a standard deviation of 4. What is the probability that a value drawn from the distribution lies between 36 and 48? A) 0.18 B) 0.32 C) 0.82 D) 0.91
*September 14, 2015 by Mark*

**algebra**

A normal distribution has a mean of 44 and a standard deviation of 4. What is the probability that a value drawn from the distribution lies between 36 and 48? A) 0.18 B) 0.32 C) 0.82 D) 0.91
*September 15, 2015 by Tyrice*

**Statistics**

We observe a sample proprotion p-hat = 0.3. If the standard deviation of the sampling distribution of p-hat is 0.04, what is the 95% confidence interval for p?
*November 10, 2015 by Morgan*

**Statistics**

The psychologists are interested in whether depressed people undergoing group therapy will perform a different number of activities of daily living before and after group therapy. Therefore, the psychologists have randomly selected 8 depressed clients in a 6-week group therapy...
*May 24, 2010 by Ashley*

**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 ...
*March 5, 2008 by Jon*

**STATISTICS PLESE HELP!!**

studies indicate that drinking water supplied by some old lead-lined city piping systems may contain harmful levels of lead. an important study of the Boston water supply system showed that the distribution of lead content readings for individual water specimens had a mean and...
*November 8, 2010 by Courtney*

**Finance**

If the CORR between stock are as follows CORR(A,B)=.85 (A,C)=.60 (A,D)=.45 and expected return is 8% and standard deviation is 20% what would be the best portfolio and why?
*June 21, 2008 by Tiffany*

**math**

If the population is bell-shaped, then the interval that is 3 standard deviation away from the center contains what percent of data in the population?
*February 7, 2009 by Sally*

**physics**

If sigma(t)^2 denotes the standard deviation in the quantity t^2, show that sigma(t)^2=2tsigma(t) I dont even know where to begin... help plzz
*February 15, 2009 by Anna*

**Algebra 2: Probability and Stats**

The scores on an exam are normally distributed, with a mean of 77 and a standard deviation of 10. What percent of the scores are greater than 87? * 68% * 16% * 84% * 2.5%
*May 24, 2010 by Skye*

**Data and statistics**

Calculate the z score for an SAT Verbal score of 510, mean of 500, and standard deviation of 100.
*July 22, 2010 by Beverly*

**math**

Find the standard deviation for the data. Round your answer to one more decimal place than the original data. {15,13,31,42,58,78}
*September 3, 2010 by David*

**statistics**

A company manufactures calculators in batches of 64 and there is a 5% rate of defects. What is the standard deviation for the number of defects per batch?
*October 15, 2010 by Rebecca*

**statistics**

A company manufactures calculators in batches of 64 and there is a 5% rate of defects. What is the standard deviation for the number of defects per batch?
*October 15, 2010 by Rebecca*

**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.
*March 13, 2011 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?
*March 17, 2011 by anne*

**statistics**

A standardized test is designed so that scores have a mean of 50 and a standard deviation of 4. What is the probability that a test score is above 54?
*April 11, 2011 by wendy*

**math**

A standardized test is designed so that scores have a mean of 50 and a standard deviation of 4. What is the probability that a test score is above 54?
*April 11, 2011 by wendy*

**statistics**

At a neighboring university, the average salary is also $45,000 and the distribution is normal. If $47,000 has a z score of 1.5, what is the standard deviation?
*April 24, 2011 by maria*

**statistics**

Calculate SS, variance, and standard deviation for the following sample of n _ 4 scores: 3, 1, 1, 1. (Note: The computational formula works well with these scores.)
*June 22, 2011 by Liz *

**statistics**

Calculate SS, variance, and standard deviation for the following population of N _ 7 scores: 8, 1, 4, 3, 5, 3, 4. (Note: The definitional formula works well with these scores.)
*June 22, 2011 by Liz *

**business statistics**

The sampling distribution of x bar must be a normal distribution with a mean 0 and standard deviation 1. true or false
*July 11, 2011 by CS*

**statistics**

A random variable X is best described by a continuous uniform distribution from 20 to 45 inclusive. The standard deviation of this distribution is approximately
*August 16, 2011 by Anonymous*

**statistics**

d. There are 200 students in a sample. How many of these students will have scores that fall under the score of 41? Mean=45 standard deviation=4
*August 29, 2011 by Dianne*

**math 3b **

In a set of 400 values, the mean is 121 and the standard deviation is 14. Estimate how many values fall in betweeb each interval
*September 15, 2011 by john*

**stats**

if IQ is normally distributed with a mean of 100 and a standard deviation of 10, what stand score (z-score) would represent a person with an IQ of 75?
*October 31, 2011 by stacey*

**statistics**

population with a mean of 53.1 and standard deviation of 4.43 Calculate z score for xbar 49.8 from a sample of size 11 Someone please please help me!
*November 6, 2011 by amy*

**statistics**

25% of the students in an English class of 100 are international students. Find mean, and standard deviation of this binomial distribution
*December 7, 2011 by brit*

**statistics**

a sample of 100 persons had a mean of 80 for a measure and the population standard deviation of 5. what ia the 99% confidence interval for the mean?
*May 6, 2012 by ourdes university*

**Math**

A shaded area reprsents approximately 95% of the scores on a standardized test. If these scores ranged from 78 to 92, whic could be the standard deviation?
*October 22, 2012 by Tanyetta*

**probability**

assume the readings on thermometers are normally distributed with a mean of 0 C and a standard deviation of 1.00 C. Find the probability P(-2.08<z<2.08), where z is the reading in degrees.
*November 26, 2012 by jiji*

**probability**

assume the readings on thermometers are normally distributed with a mean of 0 C and a standard deviation of 1.00 C. Find the probability P(-2.08<z<2.08), where z is the reading in degrees.
*November 26, 2012 by jiji*

**Statistics**

How would I find the confidence level (in %) if I am given the standard deviation, size of the random sample, and confidence interval?
*April 3, 2013 by C*

**Math**

How would I find the confidence level (in %) if I am given the standard deviation, size of the random sample, and confidence interval?
*April 3, 2013 by C*

**statistics**

Consider a normal distribution with mean 20 and standard deviation 3. What is the probability a value selected at random from this distribution is greater than 20?
*May 12, 2013 by erin*

**Statistics**

Consider the probability function. (Give your answers exactly.) P(x) = 5 − x 10 , for x = 1, 2, 3, 4 (a) Find the mean. (b) Find the standard deviation.
*May 27, 2013 by Tom*

**math**

Consider the probability function. (Give your answers exactly.) P(x) = 5 − x 10 , for x = 1, 2, 3, 4 (a) Find the mean. (b) Find the standard deviation.
*May 29, 2013 by Tom*

**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?
*June 6, 2013 by Debra*

**statistics**

A sample of n = 25 scores has M = 20 and s2 = 9. What is the sample standard deviation? a. 3 b. 4.5 c. 9 d. 81
*December 26, 2013 by Lyn*

**Statistics **

Some IQ scores are standardized with a mean of 100 and a standard deviation of 16. Using the 68-95-99.7 Rule, Determine: What percent of people would have an IQ score above 116.
*February 25, 2008 by Math help*

**Statistics **

Some IQ scores are standardized with a mean of 100 and a standard deviation of 16. Using the 68-95-99.7 Rule, Determine: What percent of people would have an IQ score of at least 132.
*February 25, 2008 by Math help*

**algebra 1**

Which statistical method best represents this set of data? 1,2,5,2,3,7,300,5,3,3 a.mean b.median c.mode d.standard deviation I'm pretty sure it's B or C, but they are both the same number.
*September 21, 2010 by Lily*

**stats**

Some IQ tests are standardized to a Normal model with a mean of 100 and a standard deviation of 16. About what percent of people should have IQ scores above 116?
*September 26, 2010 by Jamie*

**Maths**

5. Compute the two regression equations on the basis of the following data: X Y Mean 40 45 Standard Deviation 10 9 Given that the coefficient of correlation between X & Y is 0.50. Also estimate the value of Y for X=48?
*October 9, 2010 by Neeraj Bhanot*

**Trig. Math**

The mean score on a normally distributed exam is 42 with a standard deviation of 12.1. Which socre would be expected to occur less than 5% of the time? 1) 25 2) 32 3) 60 4) 67 -I know the answer is 67, but i dont know why .. PLEASE help!
*January 20, 2011 by Tami*

**stats**

We are interested in customer satisfaction ratings for a particular video game. In a group of 65 customers, we nd a sample mean of 42.95 and the standard deviation is 2.64. Find a 95% Con dence interval for u.
*July 31, 2011 by michelle*

**statistics**

a teacher decides to fail 25% of the class.Examination marks are roughly normally distributed w/a mean of 72 & standard deviation of 6. what mark must a student make to pass?
*February 22, 2012 by mike*

**statistics**

The scores on a national achievement test are normally distributed with a mean of 50 and a standard deviation of 10. Out of a group of 200 students, how many would you expect to score more than 70?
*March 20, 2012 by Anonymous*

**Statistics**

team members estimated that a group of participants spent an average of $90.00 with a standard deviation of $15.00. What is the maximum amount that you can spend and still be in the lowest 20%? and the minimum that you need to be in the highest 15%?
*March 23, 2012 by Diane*

**calculus**

a random sample of 80 students at a large school shows an average grade of 72 in algebra with a standard deviation of 4. find the t-score you would use for an 95 % confidence interval
*November 27, 2012 by emanuel hargrove*

**Statistics**

assume that adults have IQ scores that are normally distributed with a mean of 105 and a standard deviation of 15 find the probability that a randomly selected adult has an IQ between 89 and 121 ?
*December 12, 2012 by Rebecca*

**stats**

The amount that airlines speed on food per passenger is normally distributed with means $8.00 and standard deviation $2.00. What is the probability that a randomly selected airline spends more than $12.50?
*March 17, 2013 by chris*

**statistics**

The amount that airlines speed on food per passenger is normally distributed with means $8.00 and standard deviation $2.00. What is the probability that a randomly selected airline spends more than $12.50?
*March 17, 2013 by tony*

**stats.**

The amount that airlines spend on food per passenger is normally distributed with mean $8.00 and standard deviation $2.00. What is the probability that a randomly selected airline spends more than $12.50.
*April 2, 2013 by chris*

**Math**

The purchases made by customers at a convenience store are normally distributed, with a mean of $5.50 and a standard deviation of $3.50. What is the probability that a randomly chosen customer makes a purchase between $2.00 and $9.00?
*July 7, 2013 by Laurin*

**Math**

The purchases made by customers at a convenience store are normally distributed, with a mean of $5.50 and a standard deviation of $3.50. What is the probability that a randomly chosen customer makes a purchase between $2.00 and $9.00?
*July 7, 2013 by Laurin*

**statistics**

In a distribution of sentence lengths in months like the following: 6, 12, 10, 18, 24, 360; which statistic would a researcher not want to report? a. standard deviation b. mean c. range d. raw numbers
*November 29, 2013 by Jim*

**statistics, math, college**

assume that adults have I.Q scores that are normally distributed with a mean of 100 and a standard deviation 15. find p2 which is the IQ score seperating bottom 2% from the top 98%
*February 11, 2014 by andrea*

**Math**

a random sample of 28 patients across the country had an average cost of 5250 with a standard deviation of 629.at a= 0.025 can it be concluded that the mean is less than 5400
*April 27, 2014 by Anonymous*

**Prob&Stat**

If 52% of the customers at a certain grocery store regularly use coupons, what is the approximate standard deviation of the sampling distribution of the proportion for samples of size 240? 2.1% 3.2% 4.7% 10.4%
*December 14, 2014 by Bailey*

**Statistics**

Among the population of criminal justice students, the average score on the final exam was 74, with a standard deviation of 11.6. What is the probability of randomly selecting a student who earned an A (90 or better)?
*February 27, 2015 by Maddie *

**statistics**

How large a sample should be taken if the population mean is to be estimated with 99% confidence to within $72? The population has a standard deviation of $800.
*November 18, 2008 by Kennon*

**Stats**

Test the claim that the mean body temperature is less than 98.6 using a= 0.05. Assume a smaple of 16 yilded a mean of 98.2 with a standard deviation of 0.6
*April 1, 2009 by Sue*

**Stats help**

Test the claim that the mean body temperature is less than 98.6 using a=0.05. assume a sample of 16 yielded a mean of 98.2 with a standard deviation of 0.6
*April 1, 2009 by Sam*

**stats**

A club has 50 members. If there is a 10% absentee rate per meeting, find mean and standard deviation: How do you do the problem step by step
*April 16, 2009 by ce*

**Math**

A normal distribution has a mean of 20 and a standard deviation of 3.What is the probability that a randomly selected x-value from the distribution is: A)at least 14? B)at most 26? C)Between 8 and 23?
*December 13, 2009 by Sam*

**Statistics**

The mean IQ among members of a club is 118 with a standard deviation of 9.46. What percentage of the members had IQ scores of 115 or higher?
*April 28, 2010 by CJ*

**Statistics**

The population standard deviation is estimated to be $300. If a 98% confidence interval is used and an interval of +/-$75 is desired, how many cardholders should be sampled?
*July 2, 2010 by Angela*

**Financ**

What are your client’s investment proportions in your three stocks and the T-bill fund? c. What is the standard deviation of the rate of return on your client’s portfolio?
*August 11, 2010 by sam*

**MATH**

Find the z-score related to the raw score, mean, and standard deviation as follows. Assume a normal probability distribution.
*August 19, 2010 by Anonymous*

**math**

Find the standard deviation for the given data. Round your answer to one more decimal place than original data. 2,5,47,11,13,48,39,36
*September 3, 2010 by Ella*

**statistics**

The heights of a large population of students have a mean of 60" with a standard deviation of 3". What is the mean of the resulting distribution of sample means for n =16?
*October 17, 2010 by Audrey*