Monday

November 30, 2015
Number of results: 116,386

**Math**

Roughly speaking, the standard deviation indicates how far, on average, the observations are from the mean. Do you think that for the data set below the standard deviation will give a good indication of the typical deviation from the mean? 2, 3, 4, 4, 5, 5, 6, 6, 100 What ...
*February 21, 2010 by Lyndse*

**math standard deviation**

Calculate the standard deviation for the following yields of corn: 142, 161, 132, 143, 147, 145, 146, and 152 bu/ac. Are all yields obtained within one standard deviation of the mean?
*January 19, 2013 by LUA*

**math: standard deviation**

Calculate the standard deviation for the following yields of corn: 142, 161, 132, 143, 147, 145, 146, and 152 bu/ac. Are all yields obtained within one standard deviation of the mean?
*January 20, 2013 by LUA*

**Math Statistics**

In general, what is the relationship between the standard deviation and variance? a. Standard deviation equals the squared variance. b. Variance is the square root of standard deviation. c. Standard deviation is the square root of variance. d. These two measures are unrelated.
*September 29, 2012 by Misty*

**college math**

20. Calculate the range, variance, and standard deviation of the following data set: 5, 5, 6, 6, 6, 8, 8, 8, 8, 10, 10, 11, 12, 12, 20 (Points: 5) Range = 15; Variance = 225; Standard Deviation = 7.5 Range = 3.85; Variance = 14; Standard Deviation = 3.74 Range = 20; Variance...
*November 7, 2011 by Anonymous*

**math**

Suppose x is a random variable with mean and standard deviation. If a large number of trials is observed, at least what percentage of these values is expected to lie beween mean-2(standard deviation) and mean + 2(standard deviation) could someone help me i'm so lost? thank you...
*April 9, 2009 by jake*

**Statistics**

1) A Motor Company has purchased steel parts from a supplier for several years and has found that 10% of the parts must be returned because they are defective. An order of 25 parts is received. What are the mean and standard deviation of the defective parts? A) Mean = 3.5; ...
*February 15, 2009 by BEARHUG*

**Stastics**

When we convert x-value to z- score and use Standard Normal distribution, which of the following statements is true? a) The mean of z-score is zero and standard deviation of the z-scores is the same as the standard deviation of original data b) The mean and standard deviation ...
*March 7, 2010 by Mary *

**math...Please help!!!!**

This is a standard deviation question. I don't know much about standard deviation. Here it goes... Teachers making 30,000 to $60,000 the union is considering a $1,000 pay raise. A. Will the standard deviation change and the mean and the median stay the same? B. Will the mean ...
*May 18, 2015 by tanisha*

**math**

hi i need help calculating the standard error using the central limit theorem. *a population of scores contains exactly 5 scores : 2, 3, 6, 8, 11, there are 5x5=25 samples of the two scores (n=2)* i already calculated the standard deviation and mean. for the question my ...
*November 21, 2010 by ash*

**Statistics**

data from sample of 400 cases, variable has 95% confidence interval of 54.3 to 54.7 I found the mean- how do i find standard error- step by step please. Standard error = sd/√n Note: sd = standard deviation; n = sample size. You'll need to determine the standard deviation...
*April 10, 2007 by Angel*

**Math: Statistics**

My homework has a list of numbers and I'm working with standard deviation. I know the standard deviation as well as the mean and everything, but it says to find "the weight that is 3 standard deviations below the mean." What is the formula for that, and can I do it on a TI-84...
*April 19, 2011 by Justin*

**statistics**

An SRS of size n is taken from a large population whose distribution of income is extremely right-skewed and the mean income is calculated. Which of the following statements is false? a) When n > 30, the sampling distribution of is approximately normal. b) When n increases...
*April 17, 2012 by Anna*

**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**

A mean score on a standardized test is 50 with a standard deviation of 10. Answer the following a. What scores fall between 1 and +1 standard deviation? b. What percent of all scores fall between 1 and +1 standard deviation? c. What score falls at +2 standard deviations? d. ...
*April 3, 2012 by Bridget*

**statistics**

A researcher administered a treatment to a sample of participants selected from a population of 80. If the researcher obtains a sample mean of M=88. Which combination of factors is most likely to result in rejecting the null hypothesis? a, alpha level=0.01 and standard ...
*November 9, 2012 by Robbie*

**Satistics**

5. Give the standard deviation for the mean and median column. Compare these and be sure to identify which has the least variability? Standard deviation of Mean = 0.476169 Standard deviation of Median = 0.753937
*October 5, 2011 by Hope*

**Statistics**

If the standard deviation of a population is 56 and we want the standard error (the standard deviation of the sample mean) to be 14, then we need to take how many samples?
*December 20, 2010 by Jana*

**Math**

The mean of a sample of 25 was calculated as xbar = 500. The sample was randomly drawn from a population whose standard deviation is 15. Estimate the population mean with 99% confidence. B.) Repeat part (a) changing the population standard deviation to 30. C.) Repeat part (a) ...
*April 27, 2010 by Joe*

**math**

what is the standard deviation of the numbers {78, 79, 81, 82, 85}. And can you tell me how i am supposed to find the standard deviation
*November 8, 2008 by chase*

**Statistics**

hi i need help calculating the standard error using the central limit theorem. *a population of scores contains exactly 5 scores : 2, 3, 6, 8, 11, there are 5x5=25 samples of the two scores (n=2)* i already calculated the standard deviation and mean. for the question my ...
*November 21, 2010 by ash*

**math**

The standard deviation of a sample taken from population A is 17.6 for a sample of 25. The standard deviation of a sample taken from population B is 21.2 for a sample of 30. The standard deviation of the sample mean differences is_____. (Round your answer to the nearest ...
*July 15, 2015 by j*

**MATH**

Which of the following normal distributions has the smallest spread? A. A normal distribution with mean 1 and standard deviation 3 B. A normal distribution with mean 0 and standard deviation 2 C. A normal distribution with mean 3 and standard deviation 2 D. A normal ...
*December 7, 2010 by KARINA*

**statistics**

what are the mean and standard deviation of a sampling distribution consisting of samples of size 16? these sameples were drawn from a population whose mean is 25 and who standard deviation is 5. a. 25 and 1.25 b. 5 and 5 c. 25 and 5 d. 5 and 1.25 e. 25 and square root of 5 ...
*February 1, 2009 by helga*

**statistics**

150 students is 60 kg the mean of body is 70 kg withstandard deviation of 10 kg and mean weight of girls is 55 kg with standard deviation of 15kg.calculate the number of boys and the combined standard deviation. Also find whether the coefficient of deviation is hired for girls...
*August 11, 2014 by Anonymous*

**statistics/mean and standard deviation**

find the mean and standard deviation in the following probability distribution x 1 2 3 p(x) 0.2 0.6 0.2 *i think that the mean is 2 but am lost after that when it comes to the standard deviation. please show work and calculations. the more i work with numbers the more confused...
*October 23, 2010 by mary- please check calculations.*

**Statistics: Range, Average Deviation, Standard Dev**

Can someone please help me with the following math problems? I am totally lost and confused. Calculate the range, average deviation, and standard deviation for the following five distributions: A. 1, 2, 3, 4, 5, 6, 7, 8, 9 B. -4, -3, -2, -1, 0, 1, 2, 3, 4 C. 10, 20, 30, 40, 50...
*October 18, 2011 by Joy Chapman*

**College Chem**

Please tell me if this is correct...Finding the mean, the average deviation from the mean, the standard deviation from the mean, and the relative deviation from the mean...of 10.1, 10.4 and 10.6 Mean-10.4 Average deviation-0.167 Standard deviation-0.25 Relative deviation-2%
*March 19, 2010 by London*

**Statistics**

1) Find the missing parameter 1.mean 15, 30.15 %, above 50; what is the standard deviation 2.mean 75, 5.05% below 30; what is the standard deviation 3.standard deviation 9, 85.08% below 105: what is the mean 4.standard deviation 16.8, 15.62% above 18.3: what is the mean
*October 17, 2007 by LT*

**math**

the prison popuation of 9 different countries are: 50, 30, 10, 50, 60, 50, 20, 40, 50. What is the range and standard deviation? Explain. I know the range is 50, but i cant figure out the standard deviation.
*October 18, 2010 by john*

**math**

the prison popuation of 9 different countries are: 50, 30, 10, 50, 60, 50, 20, 40, 50. What is the range and standard deviation? Explain. I know the range is 50, but i cant figure out the standard deviation.
*October 18, 2010 by john*

**Math**

Repeated sample of 36 are drawn from a population with mean 52 and standard deviation 18. What is the standard deviation of the distribution of the sample means?
*March 28, 2011 by Lori *

**MATH**

what is the unknown standard deviation of this problem Ho: m=4.7 Ha: m<4.7 alpha 1% standard deviation: unknown after a random sample of 36 the mean is 4.5 with s=0.42
*December 21, 2011 by AL*

**Math**

Find the 95% confidence interval for the standard deviation of the lengths of pipes if a sample of 26 pipes has a standard deviation of 10 inches
*August 3, 2012 by Anonymous*

**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. ...
*October 9, 2012 by Anonymous*

**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 *

**math**

Using the data in the table, calculate the mean, range, variance, and standard deviation, and then answer questions e and f. Round the variance and standard deviation to one decimal place. a. Mean b. Range c. Variance d. Standard deviation e. What value is affecting the mean ...
*November 10, 2013 by Anonymous*

**Chemistry/Normal Distributions/Math**

I'm confused on how to calculate the standard deviation for this... The 95% confidence limit for calcium in control sera is reported as 9.2-10.2 mg/dl. Calculate the value for one standard deviation and the coefficient of variation for this data.
*January 21, 2013 by Maranda*

**statistics**

If a company is thinking of giving one department a 1000 bonus. Based on their means and standard deviation scores which set of employess will do better based on this information? Who should get the bonus? Employee A mean 16.875 standard deviation 4.45413 Employee B mean 12....
*November 22, 2011 by Linda*

**Math**

I have a problem on standard deviation, and I will need some help with it. Problem: Each professor in an English class give an A to students scoring above 90 and a F to those scoring below 60. Professor 1 has a normal distribution with a mean of 74 and standard deviation 7 ...
*April 12, 2011 by bikie*

**Statistics**

Check my answers please! Thanks a lot. Five students reported that the previous night they slept: 7,8,7,10,9 hours. Calculate the sample varience and standard deviation. sample varience = 1346.5 standard deviation = 36.7 Consider this. Ths standard deviation can never be ...
*February 1, 2007 by Jake*

**Advanced Functions**

1. Find the following quantities by hand (except for the standard deviation) Check your results with your calculator: a. Minimum b. Lower Quartile c. Median d. Upper Quartile e. Maximum f. Range g. Mean h. Mode i. Standard deviation 2. Is the mean or median a better measure of...
*May 2, 2011 by Anonymous*

**probability and statistics**

Suppose every student in your class got a score of 85% on an exam. What are the mean and standard deviation of those exam scores without doing any calculations? I want to say the mean is 100 and the standard deviation is 1 but I don't know why. If all students scored 85% that ...
*June 17, 2014 by Tiffany*

**stats**

Why must you square the deviation scores when computing a standard deviation using the definitional formula? Why is the computational formula easier to use when computing variance and standard deviation?
*February 5, 2013 by kelly*

**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**

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.
*October 24, 2010 by Anon*

**Statistics**

How do you figure this out? For a population that has a standard deviation of 10, what is the standard deviation of the distribution of means for samples of size 2? A-6.33 B-7.07 C-2 D-3.03
*May 7, 2010 by Amanda*

**stATS**

the standard deviation of the sampling distribution of the means is ____the standard deviation of the population under study.
*November 4, 2011 by tim*

**statistics**

population has mean 53 and standard deviation 12. Calculate the standard deviation of x bar for a random sample of size 12.
*August 18, 2014 by Bridget*

**statistics**

a mean score on a standardized test is 50 with a standard deviation of 10. What are the following: 1. what scores fall between -1 and +1 standard deviation? 2. what percent of all scores fall between -1 and +1 standard deviation? 3. what score falls at +2 standard deviations? ...
*May 11, 2012 by erica*

**Psychology/Statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size - 3. Use the formula sqrt(N^ 2/S)
*July 15, 2011 by Dawn*

**Statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size 3.
*November 15, 2010 by Barbara*

**Statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size- (b) 3.
*November 19, 2010 by Felicia*

**psy325**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size- (b) 3
*December 15, 2010 by smith*

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size 3
*January 10, 2011 by melissa*

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size- (b) 3.
*January 24, 2011 by kim*

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size- (b) 3.
*January 30, 2011 by Anonymous*

**psychology**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size - (b) 3 ?.
*February 13, 2011 by net*

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size - (b) 3 ?.
*February 13, 2011 by net*

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size- (b) 3
*April 4, 2011 by amanda *

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size- (b) 3.
*April 10, 2011 by mama*

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size- (b) 3.
*May 12, 2011 by Mae*

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size- (b) 3.
*June 13, 2011 by hope*

**statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size 3.
*June 14, 2011 by Reba*

**Statistics**

For a population that has a standard deviation of 10, figure the standard deviation of the distribution of means for samples of size: 3
*July 4, 2011 by Christy*

**statistics**

For a population that has a standard deviation of q0, figure the standard deviation of the distribution of means for samples of size-(a)2,(b)3,(c)4,(d)9.
*July 6, 2011 by Dorothy*

**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*

**Stats**

You are allowed to choose four whole numbers from 1 to 10 (including 1 and 10). You can only choose each number once though. Which of the following statements is FALSE? A. The numbers 4, 5, 6, and 7 have the smallest possible standard deviation. B. The numbers 1, 2, 3, and 4 ...
*January 20, 2012 by Nikki*

**standard deviation**

the mean is 3.5. dtandard deviation is .5. sally's score is 1.5 on test. how many standard deviations is she from the mean? billy scores 5. what is his standard score? what scale of measurement is being used? is it appropiate? why/why not?
*March 24, 2010 by dee*

**Statistics: Sample Size, Variance and Standard Dev**

Sample Size, Variance and Standard Deviation A student organization plans to ask 100 randomly selected students how much they spent on textbooks last semester. You argue for a sample of 900 students instead of 100. You know the standard deviation of the sample mean x of the ...
*September 11, 2007 by Carma*

**math**

Using the data in the table, calculate the mean, range, variance, and standard deviation, and then answer questions e and f. Round the variance and standard deviation to one decimal place. a. Mean b. Range c. Variance d. Standard deviation e. What value is affecting the mean ...
*November 8, 2013 by Anonymous*

**math**

Using the data in the table, calculate the mean, range, variance, and standard deviation, and then answer questions e and f. Round the variance and standard deviation to one decimal place. a. Mean b. Range c. Variance d. Standard deviation e. What value is affecting the mean ...
*November 8, 2013 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 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*

**HELPP math**

13,14,29,26,41,53,60,7,89,14 Based on the numbers above what is the variance and the standard deviation of the data set. I think 616.2 is the variance I think 24.83 is the standard deviation Am I correct????
*December 29, 2012 by Chris*

**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*

**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
*April 1, 2014 by Sarah Nichols*

**statistics**

help! where do i begin with this problem...in one area, monthly incomes of technology related workers have a standard deviation of $650. It is believed that the standard deviation of monthly incomes of non-technology workers is higher. A sample of 71 non technology workers are...
*July 1, 2014 by carmen*

**statistics**

A student was asked to compute the mean and standard deviation for the following sample of n _ 5 scores: 81, 87, 89, 86, and 87. To simplify the arithmetic, the student first subtracted 80 points from each score to obtain a new sample consisting of 1, 7, 9, 6, and 7. The mean ...
*June 22, 2011 by Liz *

**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*

**Maths **

Statistics The marks scored by a sample of 56 students are summarised by: N=56 Sum of x =3026 sum of(x-the mean)^2 =15378 A) calculate the mean and the standard deviation Mean I got - 54.04 (2.dp) Standard deviation I got - 16.72 (2.dp) Is this correct? B) the formula y=1.2x-...
*November 15, 2015 by Anonymous *

**Maths**

Statistics The marks scored by a sample of 56 students are summarised by: N=56 Sum of x =3026 sum of(x-the mean)^2 =15378 A) calculate the mean and the standard deviation Mean I got - 54.04 (2.dp) Standard deviation I got - 16.72 (2.dp) Is this correct? B) the formula y=1.2x-...
*November 15, 2015 by Anonymous *

**math**

Miss C gives a test to the 10 students in her first-period algebra class. The grades are 93,82,95,86,90,84,89,79,87,93 A. Find the mean and Standard Deviation of the 10 scores. B. List all the reasons for why the late class could have a different mean or standard deviation
*May 17, 2012 by Kate*

**statistics**

A production process is considered to be out of control if the produced parts have lengths with a standard deviation greater than .5 mm. A sample of 41 parts yields a sample standard deviation of .58 mm. At the .05 significance level, does this sample indicate that the process...
*December 5, 2010 by Mallory*

**Chemistry**

What is the difference between Residual Standard Deviation and Relelative Standard Deviation?
*September 11, 2010 by chloe*

**Chemistry**

What is the difference between Residual Standard Deviation and Relative Standard Deviation?
*September 11, 2010 by chloe*

**statistics**

Three students take equivalent stress tests. Which is the highest relative score? a. A score of 144 on a test with a mean of 128 and a standard deviation of 34. b. A score of 90 on a test with a mean of 86 and a standard deviation of 18. c. A score of 18 on a test with a mean ...
*April 3, 2011 by Charlie*

**statistics**

Three students take equivalent stress tests. Which is the highest relative score? a. A score of 144 on a test with a mean of 128 and a standard deviation of 34. b. A score of 90 on a test with a mean of 86 and a standard deviation of 18. c. A score of 18 on a test with a mean ...
*April 3, 2011 by Charlie*

**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 ...
*November 15, 2011 by Rob*

**math**

Can I gt some help on these questions! 1.Research subjects that are divided up based on gender, age, etc. to be compared to people of the same group is what type of design experiment? 2. A biologist collects a sample of 50 snakes. The snakes have a mean length of 25 cm with a ...
*June 20, 2013 by mysterychicken*

**Standard Deviation-What?**

I cannot figure out how to do standard deviation. standard deviation 2, 5, 47, 11, 13, 48, 39, 36
*June 14, 2010 by bart*

**Statistics**

What are the values of the mean and standard deviation of a normal standard deviation
*June 14, 2010 by Jacob*

**statistics**

Given a sample size of 38, with sample mean 660.3 and sample standard deviation 95.9 we are to perform the following hypothesis test. Null Hypothesis H0: = 700 Alternative Hypothesis H0: 700 At significance level 0.05 3. Calculate the test statistics (Tip: this is the...
*August 9, 2010 by Scott*

**statistics**

find the probability that the sample mean falls between 1.6 and 2.2. what value will you now use for the standard deviation. (Find the standard error of the mean) Mean is 1.5 and standard deviation is .25
*October 12, 2010 by Anonymous*

**MATH; STANDARD DEVIATION**

suppose that prices of a certain model of new homes are normally distributed with a mean of $150,000 use 68-95-99.7 rule to find the percentage of buyers who paid: between $150,000 and $152,000 if the standard deviation is $1200
*April 29, 2015 by CHIN*

**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*

**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*

**Math (Statistic)**

Considered the sampling distribution of a sample mean obtained by random sampling from an infinite population. This population has a distribution that is highly skewed toward the larger values. a) How is the mean of the sampling distribution related to the mean of the ...
*February 19, 2007 by Jennifer*