t-test

  1. D

    T-Test for A/B/C split population

    Hi, I am wondering if my assumption is right on the following procedure t-test. Basically, I have three different creatives running at the same time and I would like to see if the difference between response rate of the 3 creatives are statistically significant. Typically, when I have only 2...
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    Help to reply to reviewers. Is student t-test = anova for two groups?

    Hi, I have received the reviews for a paper I wrote where I have a rather complex design. But for my question I explain only the relevant bit. In a between participants design, I present participants with one of two scenarios (hedonic vs. utilitarian goal). As the classification was not...
  3. L

    Testing the significance of differences between means of two samples.

    Hi, I am currently working on an event study that compares domestic and cross border mergers and acquisitions. I have gathered two samples one for domestic (3050) and one for cross border transactions (2040). Both of the samples were selected using same criteria with respect to announcement...
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    Paired t-test using averages

    Hi, I would really appreciate if you could help me with my research design for my thesis. I am investigating a group of companies in terms of % of female employees compared to the respective industry average. The problem is that the companies are from different industries, and of course...
  5. J

    Gene expression analysis - FDR and p-values

    Hi, I'm using Affymetrix microarrays to check if there exist some differences in the gene expression of two group of animals that have been differently treated. I'm using a t-test with permutations (as my groups only have three animals and I read that it is better to use permutation if you...
  6. M

    Interpreting a paired t-test for price means

    Hey everyone, I am new to this, but I would be extremly thankful, if someone could help me with this. I research the topic of rate parity for hotels in Germany, which involves comparing rate means for different distribution channels. I have performed a paired t-test for the "phone rate...
  7. B

    superior returns market portfolio

    I have the returns and standard deviations of 10 portfolios and i want to know if they significantly beat the market portfolio. the portfolios annual retuns standar deviation 1 20% 5% 2 15% 10% 3 25% 15% 4 14%...
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    One sample t-test

    Hi, This is probably an embarrassingly easy problem but I've looked all over the place and I can't seem to find the answer, or at least I don't know the correct search terms. I have the maximum daily temperature for a particular location going back 30+ years. From this data I've calculated...
  9. N

    T-test puzzlement

    I've been pondering on this for some time and I guess i'm confused because there are so many stats tests out there. Basically my aim is to figure out if there is any statistical relevance between years of English learnt and correct answers on an English test. I have put years into months...
  10. C

    Help with t test interpretation

    Hi, I am hoping someone can help explain the following. In comparing the means of two distribution, m1 and m2, let us say m1 = 10 and m2 = 5 I am trying to interpret one-tailed and two-tailed tests. If the area to the right of critical t value (m1 - m2)/SD is 5%, then in a two-tailed...
  11. J

    T-Test with 2 samples with large absolute difference

    What do you do when the test and control volumes are significant different? Would you adjust (normalize) the differences only, or both P1 (period1) and P2 (Period2)? When you normalize, would you mix both the test and control, or would you normalize them separately? I am adding some numbers...
  12. B

    ANOVA/ANCOVA show same thing?

    An ANOVA showed that there was no main effect of personality trait on the D.V. (task performance), and an ANCOVA I conducted showed that personality trait did not influence the main effect seen in gender on task performance (there was a significant gender difference of personality trait, as well...
  13. G

    Analysis of respiration

    I am trying to analyze egg respiration data. I have 7 eggs that were measured over a 10 day period. I have data from 45 minute runs, that I have taken 5 minute averages of giving me 9 data points per day per egg. I need to analyze the change in gas over the course of the run. Then I need to 1)...
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    Transforming two non-normal sets of data for 2 sample t-test?

    Hey all, Ok so I'm trying to compare the means of two sets of data using a 2-sample t-test. Unfortunately, both sets of data are non-normal. It appears box-cox or Johnson transforms will work, but my question is, wouldn't I need to transform both sets of data using the same transform...
  15. R

    Independent sample t test!

    Hi all! One basic question I hope you can answer. I would really appreciate it :D:D I have to columns of data. Both are daily returns (scale variable). The second column does not containt as many observations as column 1. e.g column 1 column 2 0,2%...
  16. K

    T-test help with determining whether its 1 or 2 tailed?

    Hi, I need to perform a t-test to determine the relationship between US govt spending on Police and the number of Rapes annually. So I have 53 data points (53 years each variable) Firstly, can I use a t-test for this data? My first problem is that I don't get whether I should call this a one...
  17. C

    Number of samples / sub-samples required for students t-test

    I have a batch of material (25kg limestone) which contains low concentrations of several elements. 100 g samples are taken from this batch and undergo a process which may lead to the concentrations of these elements to increase or decrease (though more likely to increase). Following the...
  18. L

    Comparing the mean of top and bottom quartiles

    Hi everyone, I am going over my research and I did an analysis of the mean of 6 variables on two quartiles drawn from a particular variable. I basically assigned to each observation its corresponding quartile and then I focused on the top and the bottom ones. I did a t-test to compare the...
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    Challenge:Help with t-test using only averages, standard deviations and sample sizes!

    I want to check if the difference in my findings are statistically significantly different from the findings of an earlies study. The problem is that I do not have the full data-sets of the earlies study. " This is the data from the earlier study: (.46 percent average) [t(15) = 5.39, SEM =...
  20. D

    One Sample T-Test

    For an exercise is received speed measurements on two road points. The cars drove along an urban road (30mph) that opened into a rural road (60mph). The speed measurement of each car is taken 200 meters before (speed1) the end of the urban area and a second measurement 600 meters past (speed2)...