Monday
April 21, 2014

Search: stats

Number of results: 1,907

college stats
Z = (score-mean)/SD Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores. Multiply by 100 to convert to percent.
Monday, October 1, 2012 at 11:47pm by PsyDAG

Stats
Find the P-value for a left tailed hypothesis test with a test statistic of z= -1.77. Decide wether to reject the null if the level of significance is alpha= 0.05. Please help I've tried everything and I can't figure out how to get the right answer..
Thursday, April 17, 2014 at 10:23pm by Christina

Stats
For X ∼ Poi(λ), show that E(X) = λ and V ar(X) = λ. (Hint: Find E[X(X − 1)] = E(X2 ) − E(X).)
Monday, September 30, 2013 at 9:08pm by Becca

bus. stats
Given that math SAT scores are normally distributed (follow the empirical rule) m=500 Standard deviation=100 what is the math SAT score for someone who is in the 80th percentile of his or her class.
Wednesday, March 3, 2010 at 2:37pm by mike

bus. stats
Given that math SAT scores are normally distributed (follow the empirical rule) m=500 Standard deviation=100 what is the math SAT score for someone who is in the 80th percentile of his or her class.
Wednesday, March 3, 2010 at 2:37pm by mike

Stats
a raw score on a particular intelligence test is known to be approximately normally distributed in a population of 4th graders, with a mean of 95 and variance 81. which score has the property that there are 15% of scores in the population that are above it?
Friday, July 15, 2011 at 11:14am by Jason

stats
Use z-scores. Determine the z-value using a z-table for the top 25%. Substitute the z into the formula, along with the mean and standard deviation. Solve for x. Formula: z = (x - mean)/sd I hope this will help get you started.
Tuesday, October 23, 2012 at 4:23pm by MathGuru

Stats
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability of Z = -1.77. Is the probability in the smaller area < .05?
Thursday, April 17, 2014 at 10:23pm by PsyDAG

Stats
a. What is the probability that this year will be crash free? b. If there is a crash, what is the probability that there will be more than 2?
Thursday, January 24, 2008 at 11:03am by MoJo

stats
a) Explain the difference between sampling error and no sampling error.
Monday, January 31, 2011 at 1:31am by Andrea

stats
This is a one sample test. It is one sample because you aren't comparing groups, etc.
Tuesday, March 12, 2013 at 1:49pm by Dr. Jane

college stats
z = (p1 -p2)/sqrt(p1/n1 + p2/n))
Thursday, December 5, 2013 at 8:16pm by Kuai

stats
suppose a normal distribution has a true population mean of 18 and a true standard deviation of 2. what % of observations will be 18 or less, 18 or greater and in the range from 16 to 20?
Wednesday, June 19, 2013 at 2:54pm by dometrice

anatomy
http://www.mayoclinic.com/health/peritonitis/DS00990/ http://www.webmd.com/digestive-disorders/peritonitis-symptoms-causes-treatments According to this study, peritonitis affects men and women almost equally. http://www.rightdiagnosis.com/p/peritonitis/stats.htm
Wednesday, July 25, 2012 at 9:28pm by Ms. Sue

math check and help
I would do c) first probably the most common method to find the SD is to take differences between each of the given data values and the mean. This will give you 15 differences, some positive , some negative make a new list of the square of each of these differences. Add up ...
Saturday, June 15, 2013 at 11:37pm by Reiny

stats
If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events. In a normal distribution, mean = mode = median. What is the definition of median?
Wednesday, June 19, 2013 at 2:06pm by PsyDAG

STATS
Suppose that the average weight of students in a statistics class is 75.5 kilograms with a standard deviation of 10.3 kilograms. B. What percent of students have weights greater than 80.1 kilograms?
Monday, February 10, 2014 at 4:02pm by Tracy

prob and stats
The scores on an Economics examination are normally distributed with a mean of 77 and a standard deviation of 18. If the instructor assigns a grade of A to 16% of the class, what is the lowest score a student may have and still obtain an A? (Give your answer to two decimal ...
Friday, October 15, 2010 at 1:13am by br0Ok3

stats
95% = mean ± 1.96 SEm 99% = mean ± 2.575 SEm SEm = SD/√n
Sunday, March 31, 2013 at 6:43pm by PsyDAG

stats
3. For a particular sample of 50 scores on a psychology exam, the following results were obtained. Mean = 78 Mode = 84 Median = 80 Standard deviation = 11 1. What score was earned by more students than any other score? Why? 2. What is the variance?
Thursday, September 17, 2009 at 6:34pm by Nina

Stats
If we are testing for the difference between the means of 2 independent populations presumes equal variances with samples of n1 = 20 and n2 = 20, the number of degrees of freedom is equal to a) 39 b) 38 c) 19 d) 18.
Tuesday, August 12, 2008 at 12:34pm by Student

Stats
A "random variable" is a technical term: it does not mean a variable that is "random" in the colloquial sense. The definitions above are taken from the "variance" and "covariance" entries in Wikipedia, but can be verified at any site containing a statistical glossary, e.g. ...
Monday, September 22, 2008 at 3:39pm by David Q

Stats
the final grade averages from a fictional graduate statistics class are uniformly distributed between 66 and 96. what is the probability that a student selected at random will have a final average of between 90 and 100?
Monday, February 28, 2011 at 11:52am by John

Stats
How many green elements are required to make this a legitimate probability distribution if there are a total of 50 elements in this sample? x red blue orange brown green P(x) 0.20 0.16 0.28 0.24 Would it be 0.11??
Monday, October 24, 2011 at 3:49pm by Jennifer

stats
It would help if you proofread your questions before you posted them. What is an "r tailed test"? I don't use a calculator. I look it up on a "t table" in the back of my statistics text. df = n-1 = 8 For t = 3.204 with 8 df, .05 > p > .01
Friday, December 2, 2011 at 2:11pm by PsyDAG

stats
Z = (score-mean)/SEm SEm = SD/√n Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z scores.
Tuesday, October 9, 2012 at 10:46am by PsyDAG

stats
suppose you are to form a scatterplot oby collecting data for the given pair of variables. determine the likely direction form and strngth. Student: high grade point average, student: studying consistency
Saturday, February 9, 2013 at 1:36pm by amy

stats
Use z-scores: z = (x - mean)/sd With your data: z = (20 - 30)/9 = ? Finish the calculation. Next, look at a z-table to determine your probability. (Remember that the problem is asking "$20 or more" when looking at the table.) I'll let you take it from here.
Friday, March 29, 2013 at 9:51am by MathGuru

Stats
two tailed test for experiment with N= 24. Can't find table of t critical values, but tcv@ df=13. Compared tobt with tcv. Will this more likely create type I or type II error?
Thursday, June 6, 2013 at 7:28pm by Michele

stats
Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. See your later post. Thank you.
Tuesday, March 23, 2010 at 4:16pm by PsyDAG

Stats
Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you. See your later post.
Tuesday, February 1, 2011 at 10:41am by PsyDAG

stats
Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you. See your later post.
Wednesday, March 6, 2013 at 1:20am by PsyDAG

stats
Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you. See your later post.
Monday, May 6, 2013 at 9:11pm by PsyDAG

stats
A particular college basketball player is a 80% free throw shooter. In a game, he took 20 free throws. Find the probability he made 18 or more of his free throws.
Thursday, May 5, 2011 at 12:08pm by mike

Stats
x y 1 -10.0 2 -20.0 3 -30.0 4 -40.0 5 -50.0 - What would be the slope of this regression line? - Would the correlation between x and y be positive or negative? - How would you interpret these data in terms of linear regression?
Tuesday, October 25, 2011 at 8:35pm by Jen

Stats
The average price for new mobile homes is known to be distributed with a standard deviation of 350. if a random rample of 49 homes resulted in a sample mean of 38500, obtain a 90% confidence interval on the population mean.
Tuesday, March 24, 2009 at 10:50pm by Sally

stats
A statistics practitioner formulated the following hypothesis: H0 : ́ = 200 against H1 : ́ < 200 and learned that x = 190 n = 9 and ó = 50. The p– value of the test is (1) 0.6 (2) 0.2743 (3) 0.7743 (4) −0.2743 (5) Cannot be found with information given
Wednesday, March 31, 2010 at 1:22pm by joseph

stats
Z = (score-mean)/SD Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score. Remember to calculate for both directions.
Saturday, January 29, 2011 at 1:43pm by PsyDAG

Stats
Z = (score-mean)/SD Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion indicated. Use the related Z value to solve for the score.
Tuesday, February 1, 2011 at 2:02am by PsyDAG

stats
1. Z =( score-mean)/SD Variance = SD squared 2. Same equation, but find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to Z.
Wednesday, July 20, 2011 at 9:07pm by PsyDAG

Is this right?? Stats....
How many green elements are required to make this a legitimate probability distribution if there are a total of 50 elements in this sample? x red blue orange brown green P(x) 0.20 0.16 0.28 0.24 Would it be 0.12??
Tuesday, October 25, 2011 at 9:27am by Jennifer

stats
A soccer team is likely to score a goal at any time during a game. What is the probability it scores during the first half? Use the slash ( / ) symbol to represent fractions and be sure to reduce fractions to their lowest terms.
Wednesday, December 19, 2012 at 10:32am by Anonymous

stats
For a positive correlation, both variables increase/decrease together. For a negative correlation, one variable increases while the other decreases. I'll let you suggest the causal relations. Does T cause E, E cause T, or some third factor effect both?
Saturday, April 27, 2013 at 10:28pm by PsyDAG

STATS
Suppose a researcher observed from the analyses carried out the F-values 4.41 and 1.11. Which of the two cases are likely averages not come from the same population (ie, differences not statistically significant); a) none of the above b) 1.11 c) 4.41
Friday, October 4, 2013 at 5:57pm by MArtina

STATS
Thank you that helps a lot. I have been struggling with this. C. What percent of students weigh less than 60.1 kilograms? Z=(60.1-75.5)/10.3=-1.49 I checked the z-table and the probability is .0681. .0681*100=6.8% Is this problem correct?
Monday, February 10, 2014 at 4:02pm by Tracy

Stats
The linear correlation coefficient is a numerical value that ranges from -1.00 to +1.00. Describe in a sentence or two the meaning of each of these correlation coefficients: a) -1.00 b) +1.00
Thursday, October 20, 2011 at 11:57am by Jennifer

Stats
a) Perfect predictability, where one variable increases, while the other decreases. b) Perfect predictability, where both variable increase/decrease together.
Thursday, October 20, 2011 at 11:57am by PsyDAG

stats math
The probability of both/all events occurring is determined by multiplying the probabilities of the individual events. 13/52 * (13-1)/(52-1) = ?
Monday, November 26, 2012 at 10:47pm by PsyDAG

elementary stats
On a multiple choice test with 11 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the mean for the number of correct answers.
Thursday, February 23, 2012 at 11:18pm by Rose Bud

Stats
A loaf of bread is normally distributed with a mean of 22 ounces and a standard deviation of .5 ounces. What is the probability that a loaf of bread is < 20.75
Tuesday, March 30, 2010 at 6:32pm by Anonymous

College Stats
the average purchase per customer is 42 with a standard deviation of 4.36. using Chebysevs theorem what percentage of people will make a purchase between 54 and 30 I got 94.7 percent but i am unsure if its the correct answer can anyone verify this for me thanks
Monday, January 19, 2009 at 7:22pm by Alex

Math- Graphing Calculator Use
I'm sorry, but I'm not sure anybody will be able to help with that information. Different calculators do stats, especially, in different ways. If you specified the exact model you're using, maybe somebody reading this would have the same one, and know how it works, but that's ...
Friday, October 16, 2009 at 1:05am by jim

Stats
if a researcher were studying the effects of a teaching method on patient learning outcomes, how must he or she word the research question (different from hypothesis) to use the t-test for statistical differences? What type of data must he or she collect (interval, ratio, ...
Saturday, March 5, 2011 at 11:00pm by Rachel

TP
Thank you for using the Jiskha Homework Help Forum. Here are some sites to try: 1. http://en.wikipedia.org/wiki/Standard_deviation 2. http://www.24hgold.com/printarticle.aspx?pagedest=227403&langue=en&viewarticle=True 3. http://www.childrensmercy.org/stats/definitions/stdev.htm
Thursday, May 29, 2008 at 12:12am by SraJMcGin

stats probability
Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you. See your later post.
Monday, April 12, 2010 at 9:21pm by PsyDAG

stats homework help
Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you. See later post.
Monday, October 17, 2011 at 7:26pm by PsyDAG

Stats
The distribution of SAT verbal scores of University X's incoming freshman class (N=950) has a mean of 475. What is the value for the sum of deviation scores from the mean of this distribution?
Sunday, January 24, 2010 at 9:26pm by Jill

stats
The probability of receiving a false positive on a mammogram is 7%. If the patient receives 10 mammograms in her lifetime what is the probability that none of the tests come back as a false positive?
Saturday, April 17, 2010 at 9:43pm by kathryn

stats
H0: pi<=.60 versus H1:pi>=.60, alpha:.05 x:56 n:80 I really don't get where Alpha is involved, pls help. Thanks
Sunday, May 2, 2010 at 12:08pm by barty

stats
The weight of a product is normally distributed with a standard deviation of .8 ounces. What should the average weight be if the production manager wants no more than 1% of the products to weigh more than 7.3 ounces?
Tuesday, June 14, 2011 at 11:03am by jenny

Stats
Formula: CI95 = mean ± 1.96(sd/√n) With your data: CI95 = 88 ± 1.96(5.2/√20) Calculate for the interval.
Friday, March 2, 2012 at 4:03pm by MathGuru

Beginning of Stats
CI90 = mean ± 1.645 (sd/√n) With your data: CI90 = 12.4 ± 1.645 (2.2/√50) I'll let you finish the calculation.
Monday, December 10, 2012 at 8:45pm by MathGuru

stats
so I would have to use the independent samples t test t=m1-m2/s(m1-m2) and the standard error so what would be my df
Tuesday, March 5, 2013 at 12:11pm by Anonymous

Math, Stats
the probability is 0.6 that a person shopping at a certian store will spend less than $20. For group of size 19, find the mean number who spend less then $20.
Monday, February 21, 2011 at 1:20am by Olivia

Math, Stats
the probability is 0.6 that a person shopping at a certian store will spend less than $20. For group of size 19, find the mean number who spend less then $20.
Monday, February 21, 2011 at 1:20am by Olivia

nba stats help!!
The weight of a product is normally distributed with a standard deviation of .8 ounces. What should the average weight be if the production manager wants no more than 1% of the products to weigh more than 7.3 ounces?
Wednesday, June 15, 2011 at 4:46pm by jenny

stats
three cards are drawn from a deckof playing cards.Find the probability that the firstcard is red,the second cardis a black king,and the third card is a black king.
Monday, March 12, 2012 at 4:53pm by crystal

stats
P(18) = .8^18 * .2^2 = ? P(19) = .8^19 * .2 = ? P(20) = .8^20 = ? Either-or probability is found by adding the above three answers.
Thursday, May 5, 2011 at 12:08pm by PsyDAG

math stats
By pure chance, the student should get 50% correct. How much above that would you need to be convinced? What alpha level would you use? P ≤ .10? P ≤ .05? P ≤ .01?
Monday, October 17, 2011 at 7:35pm by PsyDAG

stats
Since you are dealing with a distribution of means rather than raw scores, use the following equation and the same table. Z = (score-mean)/SEm SEm = SD/√n 95% = mean ± 1.96 SEm
Thursday, July 26, 2012 at 9:00pm by PsyDAG

STATS. PLease help
Z = (score-mean)/SD Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to your Z score. Reverse the process for the next problem.
Tuesday, February 1, 2011 at 11:52pm by PsyDAG

stats
Given that all the answers are mutually exclusive (total=15+42+32+9=98), i.e. no answer can be counted more than once, and the subject lied with a negative result means that he/she is in the false negative category(9). So the probability is 9/98.
Sunday, February 6, 2011 at 1:49pm by MathMate

Stats...is this correct??
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to that Z score. Remember that it is below the mean, and percentile rank is % ≤ that score.
Tuesday, October 18, 2011 at 9:54pm by PsyDAG

stats word problem Please help!
Please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you.
Friday, November 23, 2012 at 3:12pm by PsyDAG

Stats
Using acronyms (e.g., tcv, bt) means nothing unless the acronym is defined. You are assuming that we use the same acronyms that you do, which in this case is not true. I can't answer unless I know what you are asking. There should be a table of t values in the back of your ...
Thursday, June 6, 2013 at 7:28pm by PsyDAG

stats
The easiest way to do this is use a binomial probability function table. You will need to determine n, x, and p. I'll give you a hint: x = 0. Once you determine P(0), then subtract the probability you find in the table from 1. That value will be your answer.
Tuesday, November 15, 2011 at 9:01pm by MathGuru

Stats
Hello Charlotte. Helen told us a lot. I f you have a 2nd account try some different from Helen's. Unofortunately i cant have access on a second account this week..
Saturday, August 3, 2013 at 6:25am by Marcov

Stats
A random sample of size 100 is drawn from a population with a standard deviation of 10. If only 5% of the time a sample mean greater than 20 is obtained, the mean of the population is ______.
Friday, December 13, 2013 at 8:31am by Matthew

Stats
Two the Prada (Italy) and Orcale (USA) are competing for a spot in the upcomings America’s cup. They race over a part of the course several times. Below are the sample times in minutes. At 0.05 significance level can we conclude that there is a difference in their mean times.
Monday, September 29, 2008 at 9:10pm by JAY

math
Z = (x - μ)/SD Plug in the values and find Z score in table in the back of your stats book labeled something like "areas under the normal distribution." Since the score is less than the mean, lower scores will be in the smaller portion. I hope this helps. Thanks for asking.
Tuesday, September 29, 2009 at 9:30pm by PsyDAG

Salary Related - Stats question
The monthly starting salaries of students who receive engineering degrees have a standard deviation of $600. What sample size should be selected so that there is 0.95 probability of estimating the mean monthly income within $150 or less?
Wednesday, November 25, 2009 at 1:58pm by Desire

stats
A random sample of 12 joggers was asked to keep track and report the number of miles they ran last week the responses are: 5.5 7.2 1.6 22.0 8.7 2.8 5.3 3.4 12.5 18.6 8.3 6.6 a) Compare the three statistics that measure central location. b) Briefly describe what each statistic ...
Monday, January 31, 2011 at 11:26am by qui

stats
A random sample of 12 joggers was asked to keep track and report the number of miles they ran last week the responses are: 5.5 7.2 1.6 22.0 8.7 2.8 5.3 3.4 12.5 18.6 8.3 6.6 a) Compare the three statistics that measure central location. b) Briefly describe what each statistic ...
Monday, January 31, 2011 at 11:28am by qui

stats
A random sample of 12 joggers was asked to keep track and report the number of miles they ran last week the responses are: 5.5 7.2 1.6 22.0 8.7 2.8 5.3 3.4 12.5 18.6 8.3 6.6 a) Compare the three statistics that measure central location. b) Briefly describe what each statistic ...
Monday, January 31, 2011 at 11:33am by qui

stats
sample of n=64 scores is obtained from population with standard deviation =15 sample mean is 10 pts greater than the poulation mean what is zscore for sample mean
Friday, March 22, 2013 at 2:55pm by tita

Stats
Find probability that a randomly selected TV will have replacement time less than 6 yrs. mean is 8.2 yrs standard deviation is 1.1 then provide warranty of 1% will be replaced what is the time length of the warranty
Monday, November 17, 2008 at 11:03am by Valerie

Stats
students reported studying an average of 9.92 hours a week, with a standard deviation of 4.54. Treating this class as the population, what percent of students study more than 12 hours a week
Sunday, December 16, 2012 at 5:30pm by Anonymous

stats
microfracture knee surgery has a 75 chance of success on patients with degernerative knees. the surgery is performed on 5 patients. find the probability of the surgery being succesful on less than 3 patients?
Tuesday, February 21, 2012 at 9:55pm by Anonymous

Stats
Calculate the expected value and standard deviation of X, the number of on the job accidents: Accidents 0,1 2 Probability .5, ?, .2 P(X=1) = E(x) = µx = Standard deviation =
Thursday, October 11, 2012 at 12:04pm by George

Stats
Nevermind! I had SS(x) = 6, and SS(y) = 6, but I kept thinking SS(xy) = 54...I wasn't solving completely. SS(xy) = 3,...so r = .5
Saturday, June 29, 2013 at 2:12pm by y912f

stats
a sample of 16 atm transactions shows a mean transaction time of 67 seconds with a standard deviation of 12 seconds. State the hypotheses to test whether the mean transactiontime exceeds 60 seconds
Wednesday, February 29, 2012 at 8:52am by Anonymous

Stats
If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events. 5/12 * 4/11 * 3/10 = ? What level of significance would you be using? P ≤ .05? p ≤ .01?
Monday, April 29, 2013 at 6:31pm by PsyDAG

health
i am doing a health project on contraceptives. where can i find the history of Lea's shield and Essure. They are both fairly new products and I could find nothing on wikipedia or anything. Also, where could I find stats on the use or non-use of contraceptives per state. http...
Sunday, June 3, 2007 at 8:36pm by maurice

Probability
1 hour is 20 minutes = 2 standard deviations away from the mean. Your stats book should have a cumulative normal distribution table. Look up 2.0 in the table. I get .9772. Ergo, 97.72% will require less than an hour.
Wednesday, March 25, 2009 at 9:16pm by economyst

stats
The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months. x 0 1 2 3 4 5 P (X=x) 0.20 0.25 0.20 0.15 0.10 0.10 Find P( X > 1)
Sunday, March 10, 2013 at 8:46am by cate

Stats
The incomes in a certain lg. population of college teachers have a normal distribution with a mean of $35,000 and st. dev. of $5000. Four teachers are randomly selected. What is the probability their average salary will exceed $40,000?
Tuesday, July 2, 2013 at 2:59pm by MT

STATS
Policy analysis searches for _____. a. infeasible courses of action b. the generation of information and collection of evidence of the benefits c. the consequences that would follow the implementation of various courses of action d. fluidity and does not always “start at the ...
Monday, December 9, 2013 at 9:10am by Jim

Prob and Stats
What does with replacement mean? what does without replacement mean?
Thursday, October 25, 2007 at 6:34pm by sarah

Statistics
Since this is not my area of expertise, I searched Google under the key words "anova test" to get these possible sources: http://en.wikipedia.org/wiki/Analysis_of_variance http://www.physics.csbsju.edu/stats/anova.html http://www.experiment-resources.com/anova-test.html In the...
Sunday, October 18, 2009 at 4:10pm by PsyDAG

Stats
n=13 xbar=46 df= 12 alpha/2= 0.025 Therefore, t= 2.179 Sd = 5.5377 t = 2.179 (42.65, 49.35) Z = 1.96 (42.99,49.01)
Thursday, December 19, 2013 at 4:21am by Kuai

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