t test

  1. victorxstc

    Nonparametric alternative to point-biserial correlation coefficient? - Which? t-test or Mann Whitney?

    A. I know from the net that for a design with one binary variable and a second variable that is continuous but is NOT normally distributed, I can use BOTH the point-biserial correlation (which is basically the parametric Pearson correlation formula) as well as the Rank Biserial Correlation...
  2. E

    What is the best T test to use for my data?

    Hi, I'm trying to work out the correct non parametric T test to use for my data. My data is made of two large groups. Each value in the first group has a corresponding later value e.g. it is showing the chance in frequency from point 1 to point 2 over time, there is many different points for...
  3. D

    One sample t test

    I have a population of 11 samples. Can I take the mean from 2 of those 11 samples and use a one sample t test to determine if the mean of the 2 samples differs from the 11 sample population? Is there a better method? Thank you
  4. M

    Choosing a method for a two-sample statistical test

    Hello everyone, I am trying to find a best method to analyze the difference between two datasets. The thing is I have a separate software where I calculated environmental impacts from production of a certain chemical substance. However, not all information was available about the actual content...
  5. M

    Statistically Significant Data for Test Engineer

    A common engineering experiment is to test something until failure to determine its ultimate break strength. Sample sizes can range from 5 to 100 pieces. I would like to know what statistical tests are used to make sure the data is good. Statistical tests that I am aware of are used to...
  6. C

    What test should i use? THESIS HELP!!

    Hi, I am currently studying Zoology at university. I am currently in my final year conducting my dissertation. I have completed my data collection and I am now on to my statistics. My dissertation looks at the relationship between light intensity and growth rate in marine sponges. I have 5...
  7. D

    Statistically significant difference between distributions only knowing the mean and std dev?

    I have 3 specimens (A, B & C) and 5 sets of observations from A & B but only 4 from C. Each observation has been reported as a mean & a standard deviation. I do not have access to the underlying data. I am curious about whether the samples are statistically different from each other as far as...
  8. E

    Statistical significance of results

    Hi, I made an experiment and I want to know if the results are significant or not. But I know nothing about statistics. In that experiment, I show a serie of 70 videos to 12 participants. Each participant should select from a list of seven choices (the same for all the videos) the emotion...
  9. F

    Testing help

    Hi all, Not sure if any one can help but here goes. For a recent research i carried out a survey on moths. I picked 2 separate areas, wooded area and a totally different area habitat wise. Area "A" and Area "B" For each area i mapped out 10 unique collecting sites. I then carried out the...
  10. A

    T test problem

    Dear all, Doing a t-test I got this results : 200 400 Mean 944.58333 960 Variance 402.08333 222.727273 Observations 12 12 Pooled Variance 312.4053 Hypothesized Mean...
  11. S

    Whether to use z test or t test

    hi team, I got the following question given below. According to me this should be solved using z test as the sample size is more than 30. But they are using t test. What is the correct method z test or t test? Please advice A social worker wants to know whether the mean annual salary of...
  12. J

    2 Way ANOVA or multiple t tests with correction?

    Hi all, I am trying to do some data analysis, and I'm not sure whether to use a 2 way ANOVA or multiple t tests with Bonferroni correction. I am looking at the effect of a chemical on bacterial binding to different polymers. So for each polymer, I want to know if there is a difference in...
  13. W

    Comparing habitat use across two different locations - mann whitney U?

    Hi, I'm really stuck with what test to use with my data. I have data on habitat use of 6 different habitat types across 2 locations and I'm unsure what test is most suitable. I thought initially mann whitney U but this doesn't seem to be working for me. I've attached the table below so you...
  14. L

    Likert scale data -can I use paired t-test? What about normality testing?

    Hey all! I have read many contradicting manuals and advice, so I decided to ask the best experts –you guys :) I have data from 40 subjects. I asked them to analyze eight short films (four sad ones, four neutral ones). I asked them to rate on a Likert scale 1 (not at all)-5 (very much) how much...
  15. T

    Comparing two groups and then the sub-groups (of the same)

    Hi I have four groups of variables A, B, C and D. The variables A and B also have (natural) sub-groups (say A1, A2, A3 and B1, B2 and B3). I want to compare them as follows: A - B - C - D (using ANOVA for 4 groups) A1 - B1 (using t test for two samples) A2 - B2 (using t test for two samples)...
  16. T

    Reporting t-test (table) + boxplot (mean, range and outliers)

    Hi I am looking for a reasonably appropriate way to report t-test along with a summary statistics. Initially I only wanted to go with box plots, and now I have to add t-test results as well. Is it a good idea to report the t-test in a table with a box plot for summary statistics as below image...
  17. H

    ANOVA maybe?

    I realized the answer but can't see how to delete.
  18. J

    2 sample independent sample t test

    Can someone please explain why you don't square the variance in this problem and do for others??
  19. C

    I failed the 4/5ths Rule. Can I prove it is not significant?

    I am a (hypothetical) employer who used an aptitude test to screen candidates for their trainability before hire. I am being sued for discriminating against Middle Eastern applicants. I have data that shows how many Blacks, whites, Latinos, and Middle Eastern people were hired and not hired...
  20. K

    Order Effects- Conflicting results from two-way ANOVA and split file t tests!

    Hello, Whilst currently working on my dissertation I decided to check for order effects (I had of course used counterbalancing as part of the design). My experiment looked at the effect of motivational prime on categorisation and probabilistic reasoning. There were two groups and both groups...