Wednesday

April 23, 2014

April 23, 2014

Number of results: 10,566

**chemistry**

problem 2 copies straight from my notes a 4.0mg/dL standard solution is needed. To prepare 100mL of the working standard, how much stock standard of a 1mg/mL solution is neeeded ? i emailed her:I didn\t know what is a stock standard , working etc. Stock standard is a standard...
*Thursday, January 21, 2010 at 2:45am by Dan_9*

**Chemistry**

You know STP stands for "standard temperature & pressure." Standard T is 273 and standard P is 1 atm or 760 mm Hg.
*Thursday, March 19, 2009 at 10:28pm by DrBob222*

**Math**

You have reversed your values. The standard error is the standard deviation — not the mean — divided by the square root of n. You also want the mean ($600) [not the standard deviation] ± 2.58 times the standard error. I hope this helps. Thanks for asking.
*Wednesday, October 1, 2008 at 11:45am by PsyDAG*

**BCIT**

A series of standard solutions of benzene in toluene solvent is to be prepared for an internal standard procedure with ethylbenzene serving as the internal standard. Tell how you would prepare the solutions, including the milliliters of benzene concentrations are to be 0.5%, 1...
*Sunday, November 10, 2013 at 5:36am by lori*

**statistics**

The "standard score" is more commonly called the "z-score". It is the number of "standard deviations" above the mean. The standard deviation is the square root of the variance, or 5 in this case. The number of data values is not needed to answer the question. A data point of ...
*Thursday, October 13, 2011 at 9:28am by drwls*

**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...
*Tuesday, April 10, 2007 at 3:17pm by Angel*

**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?
*Monday, December 20, 2010 at 3:23pm by Jana*

**homework statistics**

Assuming that you are referring to the standard deviation and not the standard error of the mean, the standard deviation will remain essentially the same.
*Friday, July 22, 2011 at 2:01am by PsyDAG*

**university of phoenix**

if someone scored two standard deviations above the mean on a standard test where the mean =100 and the standard deviation = 15, what is the person's numerical score?
*Friday, July 13, 2012 at 8:19pm by benjamin*

**Chemistry**

When 0.312g of glucose was burned in a bomb calorimeter (heat capacity 641 J/K) the temperature rose by 7.739 K. Calculate the standard enthalpy of combustion and the standard internal energy of combustion. I've calculated the standard enthalpy but am unsure of how to go about...
*Tuesday, September 25, 2012 at 11:39pm by Kalli *

**Chemsitry**

Look under Thermochemical standard state in the index. Or try Thermodynamic standard state. My FRESHMAN chemistry text has the following listed under thermochemical standard states. From Whitten, Davis, Peck, General Chemistry, 5th edition, page 554. "Keep in mind the ...
*Monday, February 25, 2008 at 5:31pm by DrBob222*

**Statistics**

Standard error of the mean is the standard deviation of the sampling distribution of the means. Take the standard deviation (15) and divide by the square root of the sample size (100) for your answer.
*Sunday, October 14, 2012 at 9:41pm by MathGuru*

**Math**

6. Factor Form : 3x3x3x3 Exponent :3^4 Standard: 81 7.2x2x2x2x2 Exponent : 2^5 Standard: 32 8. NxN Exponent N^2 Standard: N/A because N doesn't stand for anything in this problem 9. Factor Form : RxRxRxRxR Exponent : R^5 Standard : N/A
*Saturday, September 14, 2013 at 11:45am by Jerald*

**STAT**

A population has a standard deviation ó of 23 units. (Give your answers correct to two decimal places.) (a) Find the standard error for the mean if n = 11. (b) Find the standard error for the mean if n = 41. (c) Find the standard error for the mean if n = 85.
*Wednesday, April 3, 2013 at 11:46pm by Jane*

**Statistics Please Help**

One reason for standardizing random variables is to measure variables with: A. dissimilar means and similar standard deviations in like terms B. different means and standard deviations on a non-standard scale C. similar means and standard deviations on two scales D. different ...
*Sunday, May 26, 2013 at 3:33pm by Austin *

**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 ...
*Sunday, March 7, 2010 at 2:40pm by Mary *

**Standard Deviation-What?**

I cannot figure out how to do standard deviation. standard deviation 2, 5, 47, 11, 13, 48, 39, 36
*Monday, June 14, 2010 at 10:57pm by bart*

**statistics**

I am wondering what the standard deviation is: is that the standard deviation on the textbook cost, or the standard deviation on the 80 students individual average?
*Sunday, August 22, 2010 at 3:04pm by bobpursley*

**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. ...
*Tuesday, April 3, 2012 at 10:20pm by Bridget*

**statistics**

A population has a norma distribution with a mean of 50 and a standard deviation of 10. what is ther standard z-score corresponding to to 70? what is the standard z-score corresponding to 40?
*Monday, March 21, 2011 at 11:32am by hallei*

**statistics**

The standard deviation of the sampling distribution of the mean is called the standard error of the mean. I'm assuming that is what you wish to calculate. If so, determine the standard deviation and divide by the square root of the sample size.
*Tuesday, June 19, 2012 at 4:53pm by MathGuru*

**alegbra**

0.82 - 0.8 = 0.02 0.02/0.01 = 2 standard deviations You check a normal distribution table (unless you were provided with the value for 2 standard deviation already) You get : Greater than 2 standard deviation = 1 - 0.9772 = 0.0228
*Saturday, August 27, 2011 at 4:59pm by Martin*

**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...
*Tuesday, April 17, 2012 at 8:51pm by Anna*

**math**

You need to memorize this, pronto. In addition to being more understandable than the variance as a measure of the amount of variation in the data, the standard deviation summarizes how close observations are to the mean in a very nice way. Many variables in biology fit the ...
*Tuesday, April 12, 2011 at 2:00pm by bobpursley*

**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...
*Tuesday, April 19, 2011 at 11:01pm by Justin*

**chemsitry **

You have been provided 100mL of a 1000ug/ml barium standard what volume of this standard must be diluted into 50mL of ID water to produce a 30 ug/ml standard ? if you given a full 100mL of the same standard provied calculate the amount of standard and final volume required to ...
*Sunday, January 31, 2010 at 12:10pm by Samah *

**statistics**

A maintenance supervisor is comparing the standard version of an instructional booklet with one that has been claimed to be superior. An experiment is conducted in which 26 technicians are divided into two groups, provided with one of the booklets, then given a test a week ...
*Wednesday, August 5, 2009 at 2:00pm by Jeniffer*

**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? ...
*Friday, May 11, 2012 at 12:06pm by erica*

**Chemistry**

1) Assume that the reference half-cell is changed to a standard mercury-mercury (II) half-cell. a) What would be the reduction potential of a standard chlorine half-cell. c) What would be the cell potential of a standard chlorine-nickel cell. 2) For each of the following ...
*Wednesday, March 5, 2008 at 5:51pm by Anonymous*

**Chemistry**

1) Assume that the reference half-cell is changed to a standard mercury-mercury (II) half-cell. a) What would be the reduction potential of a standard chlorine half-cell. c) What would be the cell potential of a standard chlorine-nickel cell. 2) For each of the following ...
*Wednesday, March 5, 2008 at 9:34pm by Alex*

**Statistics**

I think you can calculate the Z-scores for yourself. The Z-score assumes a normal distribution, taking into account the mean and standard deviation. From calculus, we know the proportions/percentages in the normal distribution. (See a table in the back of your statistics text...
*Wednesday, July 9, 2008 at 9:06pm by PsyDAG*

**chemistry**

A scientist measures the standard enthalpy change for the following reaction to be -2923.0 kJ : 2C2H6(g) + 7 O2(g) 4CO2(g) + 6 H2O(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of CO2(g) is _________
*Wednesday, October 24, 2012 at 12:42am by Anonymous*

**7th grade math standard form scientific notation**

In standard form: 5. 3.2 x 10^3 7. 4.1 x 10^8 9. Write the average weight of a blue whale, 2.6 x 10^5, in standard form. 15. 2.5 x 10^-3 17. 1.05 x 10^-2 19. Write the size of a grain of very fine sand, about 9.35 x 10^-3 cm, in standard form. Can somebody help? I have been ...
*Friday, September 28, 2012 at 7:05pm by Delilah*

**chemistry**

for the reaction 3C2H2=> C6H6 at 25 C, the standard enthalpy change is -631 KJ and the standard entropy change is -430 J/K. calculate the standard free energy change at 25 C. show all work!
*Tuesday, December 4, 2012 at 8:28pm by ashley *

**statistics**

Empirical rule is 68-95-99.7, which means approximately 68% is between 1 standard deviation about the mean, approximately 95% is between 2 standard deviations about the mean, and approximately 99.7% is 3 standard deviations about the mean. 124.4 is two standard deviations ...
*Monday, September 19, 2011 at 2:00pm by MathGuru*

**stats**

The standard error of the mean of a sample of N is the population standard deviation divided by sqrt(N), so if the second parameter of your N(188, 41) is the population standard deviation, the SEM should be 1.297. So you need to find out how many standard errors each of 185 ...
*Friday, October 12, 2012 at 8:52pm by David Q/R*

**chemistry 2**

for the reaction 2C2H2(g)=>C6H6(l) at 25 C, the standard enthalpy change is -631 kJ and the standard entropy change is -430 J/K. calculate the standard free energy change at 25 C. show all work Help please!
*Wednesday, December 5, 2012 at 3:07am by concerned chem student*

**chemistry 2**

for the reaction 2C2H2(g)=>C6H6(l) at 25 C, the standard enthalpy change is -631 kJ and the standard entropy change is -430 J/K. calculate the standard free energy change at 25 C. show all work Help please!
*Wednesday, December 5, 2012 at 3:24pm by concerned chem student*

**math**

i dont understand standard form math and i have to questions what is nine hundredths in standard form and sixteen and six tenths in standard form?
*Tuesday, September 23, 2008 at 4:42pm by tamija*

**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.
*Saturday, September 29, 2012 at 6:41pm by Misty*

**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 ...
*Sunday, November 21, 2010 at 9:00pm by ash*

**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 ...
*Sunday, November 21, 2010 at 9:01pm by ash*

**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; ...
*Sunday, February 15, 2009 at 1:59pm by BEARHUG*

**mass media**

I'm not sure what you mean by "representative profile." For an estimate of a mean, ± 2 standard error give approximately a 95% confidence interval, leaving a 5% margin of error. Standard error = standard deviation/sqrt of N, where N = number in the sample. I hope this helps. ...
*Monday, April 14, 2008 at 9:15pm by PsyDAG*

**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?
*Saturday, January 19, 2013 at 1:03pm 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?
*Sunday, January 20, 2013 at 12:19pm by LUA*

**Statistics**

What are the grand mean, the UCL and the LCL of a control chart for the mean? Why do you suppose + (with underline) standard errors are used in control charts and not two standard errors or even one standard error?
*Monday, June 30, 2008 at 9:35pm by Crystal*

**chemistry**

how do i do this \? a 4.0mg/dl standard solution is needed. To prepare 100ml of the working standard. How much stock standard of a 1mg/ml (100mg/dl) solution is needed. i dont understand this conceptually / thanks
*Thursday, January 21, 2010 at 2:45am by Dan_9*

**behavioral statistics**

How could you use standard scores and the standard distribution to compare the reading scores of two students receiving special reading resource help and one student in a standard classroom who does not get special help?
*Tuesday, February 25, 2014 at 8:29pm by michelle*

**Chemistry**

Which of the following is NOT true about the thermodynamic standard state? A. A gas is in its standard state when its pressure is 1.00 atm and its temperature is 25C. B. An aqueous solution is in its standard state at a concentration of 1.00 M. C. A pure liquid is in its ...
*Sunday, February 24, 2008 at 7:50pm by Anonymous*

**chem**

Which of the following is NOT true about the thermodynamic standard state? A. A gas is in its standard state when its pressure is 1.00 atm and its temperature is 25C. B. An aqueous solution is in its standard state at a concentration of 1.00 M. C. A pure liquid is in its ...
*Sunday, February 24, 2008 at 8:13pm by Anonymous*

**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?
*Wednesday, March 24, 2010 at 10:11am by dee*

**Statistics**

There is a formula you can use to find part b). 1 - (1/k^2) = .84 (or 84%) k = 2.5 (standard deviations) Therefore, find the amounts within 2.5 standard deviations of the mean. Remember that one standard deviation is equal to $340. I'll let you take it from here.
*Tuesday, June 11, 2013 at 1:44pm by MathGuru*

**chemistry**

Which of the following is NOT true about the thermodynamic standard state? A. A gas is in its standard state when its pressure is 1.00 atm and its temperature is 25C . B. An aqueous solution is in its standard state at a concentration of 1.00 M. C. A solid is in its standard ...
*Wednesday, February 20, 2008 at 1:52pm by jina*

**Chemsitry**

Which of the following is NOT true about the thermodynamic standard state? A. A solid is in its standard state when the atmospheric pressure is 1.00 atm and the temperature is 25C. B. An aqueous solution is in its standard state at a concentration of 1.00 M. C. A gas is in ...
*Monday, February 25, 2008 at 5:31pm by Anonymous*

**chemistry**

Which of the following is NOT true about the thermodynamic standard state? A. A pure liquid is in its standard state at 25C and a vapor pressure of 1.00 atm. B. An aqueous solution is in its standard state at a concentration of 1.00 M. C. A gas is in its standard state when ...
*Sunday, May 17, 2009 at 6:21pm by jeff*

**computers**

Although label choices vary for different printers, your textbook recommends __________ for laser and ink jet printers. A. Avery standard, 5160, Address B. Avery standard, 6150, Label C. Avery standard, 6150, Address D. Avery standard, 5160, Label I've looked through the book...
*Wednesday, June 27, 2012 at 6:20pm by julia*

**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 ...
*Sunday, February 21, 2010 at 12:21pm by Lyndse*

**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...
*Thursday, April 9, 2009 at 5:58pm by jake*

**Sampling Distribution**

Sampling Distribution Complete solutions and illustrations are required. 5.The standard deviation of a variable is 15. If a sample of 100 individuals are selected compute for a.The standard error of the mean. b.What sample size is necessary to double the standard error of the ...
*Wednesday, February 27, 2013 at 10:55pm by Tina*

**Chemistry**

Which of the following is NOT true about the thermodynamic standard state? A. A solid is in its standard state when the atmospheric pressure is 1.00 atm and the temperature is 25C. B. A pure liquid is in its standard state at 25C and a vapor pressure of 1.00 atm. C. An ...
*Saturday, May 17, 2008 at 8:09pm by Tom*

**chemsitry**

c. Use the enthalpy diagram provided above and apply Hess’s Law to determine the standard enthalpy of formation for C12O36H20N12 (s) using the results from part (a) and the following values: The standard enthalpy of formation of gaseous carbon dioxide is -393.5 kJ/mol The ...
*Saturday, October 23, 2010 at 2:36pm by Nora*

**Math**

It depends on the use of the term 'standard form'. It can mean the usual representation of an equation, for example the equation for a straight line as y=mx+c could be described as standard form. 'In standard form' can also mean 'in scientific notation.'
*Wednesday, October 10, 2007 at 7:38pm by Dr Russ*

**Biochem**

It isn't clear from your post if the standard was diluted in a manner similar to that of the sample. I will assume it was; if not you will need to make a adjustment for the dilution. If the sample is 4.5 mM and gave A = 0.5, it must be a higher concn than the standard at A = 0...
*Sunday, September 30, 2012 at 9:50pm by DrBob222*

**algebra**

variance = 4, so standard deviation = 2 (because squareroot of 4 is 2) 160 - 166 = -6 = -3 standard deviation. You take out a normal distribution table and you find out that a standard deviation of -3 or less happens only 0.13% of the time. Answer : 0.13%
*Saturday, August 27, 2011 at 11:47pm by Martin*

**Stasistic**

Since the Z and T score are standard for any normal distribution, you don't even need to know the mean or standard deviation of that distribution to answer your questions. Z score = standard deviations away from the mean. T score = 50 + 10Z
*Monday, June 20, 2011 at 3:44pm by PsyDAG*

**standard deviation**

The Z score indicates standard deviations from the mean. It is accurate as long as the distribution is normal. Z = (score - mean)/standard deviation You can do the calculations.
*Wednesday, March 24, 2010 at 10:11am by PsyDAG*

**chemistry**

In choosing a primary standard we generally choose something that 1. All of these are properties we want in a primary standard. 2. has a low percent purity. 3. None of these are properties we want in a primary standard. 4. has several different possible reaction pathways. 5. ...
*Wednesday, September 19, 2012 at 5:06pm by cheri*

**Chemistry**

The bar goes in for partial pressure of H2 gas so if we have H2 ==> 2H^+ + 2e then E = Eo - (0.059/2)*log [(H^+)^2/pH2] I'm unclear if the bar has become the standard of if your prof is using 1 atm for the standard. The difference a. if bar is standard, you simply ...
*Monday, March 29, 2010 at 9:10pm by DrBob222*

**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
*Tuesday, October 12, 2010 at 8:13pm by Anonymous*

**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
*Wednesday, October 5, 2011 at 2:21pm by Hope*

**P-Chem**

The equilibrium constant K for the hydrolysis of adenosine triphosphate (ATP) to adenosine diphosphate (ADP) and phosphate is 1.66X10^5 at 37 degrees celcius, and Standard Delta H is -20.1 kJ/mol. Calculate Standard Delta S for the hydrolysis at 37 degrees celcius. On the ...
*Friday, October 20, 2006 at 6:38pm by Angela*

**Chem history**

The standard is C-12, which is a widely naturally occuring isotope of carbon, found in nature. Silicon is not commonly found in nature uncombined. The selection of the international standard was arbitrary, and could have been any element. One usually wants in a standard: ...
*Monday, February 25, 2008 at 1:16am by bobpursley*

**Standard Error Of Mean?**

In a random sample of 30 tires of the same type, it is found that the average life span of a tire is 36,200 miles with a standard deviation of 3,800 miles. Find the standard error of the mean. a 126.67 b 693.78 c 9.53 d 587.24
*Monday, April 23, 2012 at 8:43pm by Help Please?*

**Chemistry**

The heat of formation must be an equation for the formation of the compound (1 mol) on the right from elements on the left. I is OK BUT it is for two moles. II is no go since C2H2 is not an element. III is no go since O3 is not a standard state of oxygen (O2 is the standard ...
*Sunday, July 11, 2010 at 2:04pm by DrBob222*

**Statistics**

Mean = 14 Standard deviation = 2 Two standard deviations below the mean would be 10. Three standard deviations above the mean would be 20.
*Saturday, November 3, 2012 at 11:31pm by MathGuru*

**statistics**

How is the standard error of the mean influenced by sample size and standard deviation?
*Saturday, October 6, 2012 at 3:12pm by Nina*

**Statistics**

standard error= standard of population/sqrt(sample size)
*Monday, December 20, 2010 at 3:23pm by TutorCat*

**algebra**

Standard deviation = 4 Two standard deviations = 8 75 - 8 = ? This will be your mean.
*Tuesday, October 29, 2013 at 6:03pm by MathGuru*

**statistics**

Standard Error = standard deviation divided by the square root of the sample size
*Tuesday, October 4, 2011 at 3:53pm by MathGuru*

**statistics**

What are the values of the mean and standard deviation of a standard normal distribution? μ = σ =
*Saturday, February 4, 2012 at 2:46pm by Jr*

**statistics**

I'll explain 2 of these questions; see if you can figure out the other two. 4.1 The mean will be changed and the standard deviation will remain the same. There will be no change in standard deviation since each score and also the mean increase by constant K. 4.3 You can use ...
*Thursday, October 25, 2007 at 8:11pm by MathGuru*

**Chemistry**

Standard T is 273 Kelvin (0 degrees C). Standard pressure is 1 atmosphere or 760 mm Hg.
*Monday, May 4, 2009 at 5:09pm by DrBob222*

**statistics**

The standard deviation of a distribution is 28. If a sample of 289 is selected, what is the standard error of the mean?
*Wednesday, August 25, 2010 at 2:12pm by damian*

**statistics**

Standard error of the mean = standard deviation divided by the square root of the sample size
*Wednesday, August 25, 2010 at 2:12pm by MathGuru*

**BioChem**

If you run an unknown sample and it is darker than your highest standard on your standard curve, what do you report as the concentration?
*Monday, October 31, 2011 at 10:33pm by Dreamland11*

**statistics**

Standard error of the mean: Standard deviation divided by the square root of the sample size.
*Monday, June 18, 2012 at 4:51pm by MathGuru*

**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
*Wednesday, October 17, 2007 at 2:24pm by LT*

**chemistry**

I have to find delta G from a problem. Not the standard free energy, from the change in engery. So this delta G does not have the degree sign above. The equation i used was deltaG=standard G+RTlnQ If deltaG was a positve number, what does that tell me. I know that if the ...
*Sunday, March 1, 2009 at 10:32pm by Anonymous*

**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 ...
*Tuesday, September 11, 2007 at 4:26pm by Carma*

**chemistry**

Why is the standard reduction potential E, for the standard hydrogen electrode 0.00V? Please help me explain the reason why to this problem
*Thursday, May 22, 2008 at 2:14am by jennifer*

**chemistry**

Why is the standard reduction potential E, for the standard hydrogen electrode 0.00V? Please help me explain the reason why to this problem
*Thursday, May 22, 2008 at 2:28pm by kristine*

**Math-**

I didn't do the standard deviation for each one because I didn't know how, can you help?, if not do you have something ( a link to forward me to) so I can review standard deviations. I do appreciate your help.
*Sunday, March 31, 2013 at 6:25pm by Liz*

**math help!!!!**

Compute the mean and the standard deviation. The mean is 71.1. You do the standard deviation. It is about 15. There are websites online that calculate it for you. 49 is 22.1 below the mean. The z-score is -22.1/(standard deviation)
*Monday, January 10, 2011 at 4:31pm by drwls*

**Statistics**

If 79 = 1.8 standard unit and 64 = .8 standard units, wouldn't it be logical to assume that each standard unit is 15 points? 79-64 = 15 1.8-.8 = 1 That information should help.
*Thursday, November 12, 2009 at 12:30am by PsyDAG*

**Chemistry**

In a standard hydrogen electrode, why does increasing the partial pressure of H2 gas reduce the standard potential (E) of the cell?
*Tuesday, April 5, 2011 at 7:59pm by John*

**Chemistry**

How do I find the pH of pure neutral H2O at o degrees celsius by using standard enthalpies and standard entropies
*Thursday, April 21, 2011 at 3:16pm by Tanya *

**Statistics 343**

A sample has a mean of 120 and a standard deviation of 20.0. Find the value of x that corresponds to each of these standard scores: a. z = 0.0
*Sunday, July 10, 2011 at 10:20pm by UoP*

**statistics**

If a population has a standard deviation ó of 25 units, what is the standard error of the mean if samples of size 100 are selected?
*Friday, December 2, 2011 at 4:37pm by dee*

**statistics**

If a population has a standard deviation ó of 25 units, what is the standard error of the mean if samples of size 100 are selected?
*Friday, December 2, 2011 at 5:52pm by deandra*

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