Number of results: 18,231
A pharmaceutical manufacturer forms tablets by compressing a granular material that contains the active ingredient and var. fillers. The hardness of a sample from each lot of tablets produced is measured to control compression. The target values for the hardness are mean=11.5...
Wednesday, February 21, 2007 at 8:35pm by jisun
In a study that was highly published doctors discovered that aspirin helps prevent heart attacks. The research project which was scheduled to last 5 years employed 22,000 american physicians (all male). Half took an aspirin tablet 3 times a week while the other half took a ...
Friday, February 23, 2007 at 4:24pm by Jason L
2 samples were collected to determine whether there was a difference between two weight loss methods targeting men. The average weight loss method is provided for the 2 samples along with the respective standard deviations. Is the second method - with an average weight loss of...
Friday, February 23, 2007 at 4:33pm by Jason L
25% of the houses in a certain area have swimming pools. if 5 houses from this area are selected at random, what is the probability that no one has a swimming pool. 1.1 at least two have swimming pools. question2 an automatic boling machines fills cola into 2litre (200cm) ...
Friday, April 27, 2007 at 3:35am by mary
I have a question on a quiz and I dont even know where to begin on figuring out the question... please help: Measurements on the percentave of enrichment of 12 fuel rods used in a nuclear reactor were reported as follows: 3.11 2.88 3.08 3.01 2.84 2.86 3.04 3.09 3.08 2.89 3.12 ...
Tuesday, June 5, 2007 at 7:25pm by Haley
You can use a one-sample z-test on this data. Null hypothesis: Ho: µ = 3 -->meaning: population mean is equal to 3 minutes Alternate hypothesis: Ha: µ < 3 -->meaning: population mean is less than 3 minutes Using the z-test formula to find the test statistic: z = (...
Monday, June 23, 2008 at 1:09pm by MathGuru
Let's set up the null and alternative hypothesis, find a formula to use, then go from there. Null hypothesis: Ho: p = .42 -->meaning: population proportion is equal to .42 Alternative hypothesis: Ha: p > .42 -->meaning: population proportion is greater than .42 [ Note...
Monday, October 29, 2007 at 3:54pm by MathGuru
Middle School Science
I can't find the definitions for the following science terms anywhere: known sample positive test negative test can anyone help?
Monday, November 12, 2007 at 8:52pm by Adam
Hypotheses: Ho: pY = pR (R = red trucks; Y = yellow trucks) Ha: pY < pR You can use a binomial proportion 2-sample z-test for this kind of problem. Here is one formula for this type of test: z = (pY - pR)/√(pq(1/n1 + 1/n2) p = (x1 + x2)/(n1 + n2) q = 1 - p pY = 4/...
Thursday, June 19, 2008 at 5:14am by MathGuru
You can also use a binomial proportion 2-sample z-test for this type of problem. Look at my response to your previous post to see how to set up this problem. Remember that this will also be a one-tailed test.
Thursday, June 19, 2008 at 5:19am by MathGuru
What is the purpose of a tukey test? Why can't we compare all the posible pairs of group means using the two-sample t-test?
Monday, February 11, 2008 at 11:12pm by Dana
Both parts are using one-sample two-tailed tests. Since the sample in part a) is so small, you can try a one-sample t-test and for part b), a one-sample z-test. For the t-test: t-statistic = (sample mean - population mean)/(standard deviation divided by the square root of the ...
Thursday, February 28, 2008 at 1:37am by MathGuru
Let's try a binomial proportion one-sample z-test for this problem. I'll give you the setup for the calculations and let you take it from there. Formula with your data included: z = (.82 - .9)/√[(.9)(.1)/100] Note: .82 is 82/100; .9 is 90% from the problem; .1 is 1-.9; ...
Saturday, July 5, 2008 at 11:50pm by MathGuru
Null hypothesis: Ho: p = .95 -->meaning: population proportion is equal to .95 Alternative hypothesis: Ha: p > .95 -->meaning: population proportion is greater than .95 Using a formula for a binomial proportion one-sample z-test with your data included, we have: z = ....
Sunday, June 8, 2008 at 7:45pm by MathGuru
Can people really identify their favorite brand of cola? At a= .05, is the correctness of the prediction different for the two types of cola drinkers? Since it is 2 x 2 table, try also a two-tailes two-sample z test for n1 = n^2 and verify that z2 is the same as your chi-...
Monday, June 23, 2008 at 5:12am by Gayla
Try a one-sample z-test for your problem. Using the z-test formula to find the test statistic: z = (sample mean - population mean)/(standard deviation divided by the square root of the sample size) z = (3.69 - 3.65)/(.24/√45) Finish the calculation. Use a z-table to ...
Thursday, September 11, 2008 at 1:29am by MathGuru
A few hints to get you started: 1. If H1 shows a specific direction, the test is one-tailed. If H1 does not show a specific direction (could be in either tail of the distribution curve), the test is two-tailed. 2. Use a one-sample z-test formula to determine the test statistic...
Friday, October 3, 2008 at 3:08pm by MathGuru
I am having difficulty deciding which basic statistical test I should use to compare two means. I am comparing calorie consumption amongst people with different levels of physical activity. Is an independent two sample t-test acceptable?
Monday, December 8, 2008 at 6:06am by Karen
For a single-sample t-test the t(17) = 2.90, p<.02, how many were in the study?
Saturday, March 30, 2013 at 7:53pm by Laurie
Here is a hint: The degrees of freedom for a single sample t-test is (n-1).
Saturday, March 30, 2013 at 7:53pm by MathGuru