Results 1 to 3 of 3

Math Help - two sample t test - comparing rates

  1. #1
    Newbie
    Joined
    Jul 2012
    From
    UK
    Posts
    2

    two sample t test - comparing rates

    Hi

    I have been asked to evaluate the below results from a fundraising campaign, and conclude whether there are any differences between the TEST and CONTROL groups. Specifically, i need to decide whether the response rate and income per invested are significantly higher in the TEST group.

    I would be grateful for any help with this, i think i may have the answer for the response rate test. I believe this would involve a two sample t test using Mailing volume as the 'n1' and 'n2', and estimating the sample standard deviation as SQRT(p*(1-p)) where p is the observed response rate in both samples, given that these are bernoulli trials. I would be grateful if anyone could confirm this approach, and how i could carry out a similar analysis for income per invested (which doesnt constitute a bernoulli trial).

    Many thanks
    Colin

    CONTROL VS TEST Mailing Volume Responses Income Cost response rate income per invested
    TEST 2140 211 8,845 1,070 0.099 8.27
    CONTROL 576 32 1,489 288 0.056 5.17
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28

    Re: two sample t test - comparing rates

    Follow this example.


    Hypothesis Test: Difference in Proportions


    Make p_1 the response rate for the test group and  p_2 the response rate for the control group

    Use the case where H_0: p_1 - p_2 \geq 0
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jul 2012
    From
    UK
    Posts
    2

    Re: two sample t test - comparing rates

    Thanks for this very quick response. But if i need to estimate the standard deviation would it not be a t-test (as opposed to analysis using the Normal Distribution)? Im fine with the logic other than that.

    Also, can you advise how i might compare 'income per invested' in the same way?

    I really appreciate the help here

    Bests,
    Colin
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Question about F-Test for comparing multiple regression models
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: March 10th 2011, 07:38 PM
  2. One sample t-test CLASHING with paired sample t-test?
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: February 15th 2011, 10:34 PM
  3. Comparing means from SAME sample
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: September 1st 2010, 01:57 PM
  4. Which test to use? Comparing two samples
    Posted in the Statistics Forum
    Replies: 1
    Last Post: April 16th 2009, 09:59 AM
  5. Comparing Response Rates
    Posted in the Statistics Forum
    Replies: 5
    Last Post: December 26th 2008, 10:15 AM

Search Tags


/mathhelpforum @mathhelpforum