hypothesis testing

  1. T

    Hypotheses testing - Interpreting r=" . "

    Hello, I'm interpreting data at the moment from my Pearson Correlation analysis for different groups of respondents. One of my group only consists out of two respondents. As a result for the one Pearson correlation analysis I get p=-1 and for the other p=1 as well as both times (Sig 2tailed)...
  2. H

    Hypothesis testing and minitab

    Hi New to the site - I've managed 11 out of 13 questions for my final set of Master Black Belt homework but now stuck! Can anyone offer an explanation to this question and how it could be answered in minitab? I've had a very extensive look online and found multiple solutions but cannot work...
  3. H

    We did an experiment and don't know how to start/proceed with statistics?

    We had to do an experiment in my research methods class. Me and my group did an experiment where we tested if participants remembered words better with or without pictures that match the words. So now we have two sets of data: One set with the number of words they remembered and one set with the...
  4. S

    Two Tailed Hypothesis Testing

    A sales compnay wants to forecast its sales . There are 2 samples with n1 =30 and n2=30 .Since its a small sample I did paired t- Test in excel . I got critical T value is greater than the calculated t value. Im ok till this part. Now in order for the sales company to break even, the average...
  5. N

    Statistical analysis - Work Delay - Some tests relations

    Suppouse that we have a dataframe called dataWork with data from a database. There are several variables and 2 of them are: - Delay: time (minutes) to get to work (could be empty) - Nocturnal: 0 (work by day) 1 (work by night) we want to know the relation between delay and nocturnal. So...
  6. A

    Statistical inference.

    Hi there, I would like to ask a couple of basic questions: 1. What is the difference between estimation and hypothesis testing? I mean are they two options for inference? or estimation of the parameters comes first and then we apply the hypothesis testing? 2. How can I determine what is...
  7. A

    Goodness of fit tests

    Hi there, Adding to my previous questions: 1. Why do I need goodness of fit test? I mean when I get a set of data should I always suggest a distribution for it and then do test the goodness of fit for this hypothesis? or it comes in sequence of :1.estimation 2.goodness of fit 3.hypothesis...
  8. A

    Statistical inference

    Hi there, I would like to ask a couple of basic questions: 1. What is the difference between estimation and hypothesis testing? I mean are they two options for inference? or estimation of the parameters comes first and then we apply the hypothesis testing? 2. How can I determine what is...
  9. N

    HLM Multilevel Modeling - Deviance Statistic Disappeared with MI

    Hi Everyone, I am using HLM 7 for multilevel modeling. I recently started using the Multiple Imputation function in the program, which pools data from 10 datasets that you upload directly into the program. The models run but I can't get the program to give me deviance statistics for model...
  10. R

    Comparison of one outcome to all the other outcomes

    Here is some data to play with set.seed(1e4) color = factor(c(rep("blue",20), rep("red",20), rep("yellow",150)), levels=c("red","blue","yellow")) x1 = rnorm(20+20+150,12,3) x2 = c(rnorm(20,5), rnorm(20,5), rnorm(150,7)) x3 = c(rnorm(20,7), rnorm(20,5)...
  11. P

    Z Test with unknown sample size

    How would I conduct a z test when I don't have "n"? The instructor never went over what to do without an "n". It has always been provided. Please help me! The national norm for fifth graders on a standardized test of scientific literacy is 37 (σ = 3). Mrs. Jackson determines that the mean...
  12. F

    Which statistical model to choose?

    Hey guys, I have a few hypotheses in a randomized control trial that I would like to test: 1) Effect of a treatment on several outcome variables (some of them are continuous, some of them are dichotomous) 2) Moderating effect of commitment in the treatment on effect 1) - Commitment...
  13. F

    A priori Power Analysis

    Hey Guys, I am a newbie and have a question on power analysis. I would like to measure the effect of an intervention on various measures and have several control variables. I believe it is the best to use a multiple linear regression model with a dummy variable for the treatment. Therefore, I...
  14. H

    Correlation matrix with significance

    Does anyone have a ready-made function or know a way to produce a correlation matrix with asterisks marking significance levels in R?
  15. S

    Statistical test for algorithm performance

    I am developing different algorithms for a class of optimization problems. I have several problem instances in this class (some from real applications, some randomly generated), which do not differ in terms of structure, but in terms of data. I would like to compare the performance of my...
  16. D

    [SPSS - Hypothesis testing] Controlling for a variable. ANCOVA?

    Hi! I am using open data from New York City's yellow cabs and the in 2013 introduced citibikes (bikesharing service) to see if the introduction of the citibike led to a decrease in business for the yellow cabs. Additionally, I would like to control for the weather. I have weather information...
  17. S

    Need Help With statistic work. Hypothesis testing

    Question 1 Below are the quarterly returns on investment (in £000s) of two different investment projects, which had the same initial outlay. There is a sample of 16 quarters of returns and your manager has asked you to investigate the relative performance of each project. In particular, your...
  18. U

    Hypothesis Testing - Obtaining T-Stats and Critical T-Values

    Dear all, I have been given the following question I don't really understand how to interpret this question. Commonly, hypothesis questions refer to one sampled variable with a given criterion. But this question just states that I must test the null hypothesis that one variable is not...
  19. C

    Defining Contrast Matrix

    Suppose I have a binary Covariate X which is defined as X = \begin{cases} 1, & \text{if treatment group} \\ 0, & \text{if placebo group} \end{cases} The model is \mathbb E[Y] = \beta_0 + \beta_1X, where Y is a continuous random variable. If X=0, then \mathbb E[Y] =...
  20. B

    Repeated t-tests or ANOVA for discerning difference between two treatments

    Hello, I am helping my sister with some statistics in her master's dissertation in behavorial/social sciences. I have studied a couple of courses on statistics/probability, but my proficiency could certainly be better. I have this book "An Introduction to Mathematical Statistics and it's...