Pet owners : 8 1 3 3 4 3 5 2 11 5 No-pets : 10 5 10 7 5 4 9 6 12 9 5 8 What is the design of this study? ____________________________ n = ____ people What is the IV? __________ What is the DV?...

Pet owners: 8   1   3   3   4   3   5   2   11   5


No-pets: 10   5   10   7   5   4   9   6   12   9   5   8

1. What is the design of this study? ____________________________ n = ____ people


2. What is the IV? __________ What is the DV? _____________________


3. Is the hypothesis underlined above one-tailed or two-tailed? _______


4. State the Hypotheses in symbols and words:
   .
   

H₀: _____________   in words:

H₁: _____________   in words:

Create an Excel data file organized by IV and DV.  Variables: 1) pet_ownership and 2) DR_visits.

     (This time do not code pet_ownership as a dummy variable (1,2); instead, write

pet

or
no pet
as the

      group categories in the Excel file.)

Open this dataset in JASP.
Perform an
Independent Samples
t-test
by selecting

T-Tests > Classical > Independent Samples t-test

.
Select
DR_visits
as the

variable

and
pet_ownership
as the

grouping


variable
.
Check off
Location Parameter,
95% Confidence Interval, and
Descriptives
.

1. Fill in the following from the Descriptives output table.

                     Pet owners                                Non-owners

            Means of visits:                        ________________                  _____________

            Std. Deviation                          _______________                    _____________

            Std. Error of Mean                    _______________                    _____________

Before we look at the results of the
t-test, let’s plot the means and confidence intervals.
Check off the
Descriptives plots
option
below
Additional Statistics. This creates a graph with the mean for each group plotted with bars out a distance that represents the 95% confidence interval for each group mean.

1. Describe the graph in terms of the amount of overlap of the bars (e.g., approx percentage of overlap) ___________________________________

Now, let’s test the
Equality of Variances
between groups. Under
Assumptions Check,
check off the
Equality of variances
option.
If the p-value is greater than .05 the variances are equal - use the student’s t-test value we already calculated. If p is less than .05, we will need to use the Welch t-test, which can be calculated by checking off
Welch
under
Tests. Fill in the information below using the appropriate test:

1. Is the assumption of the equality of variances met according to this test? _______

1. Fill in these values from the tables:

t = ____________ df = ____________ Sig. or p level  (2-tailed) = ______________       Mean Difference = ______________     Std. Error of Difference = _____________ 95% Confidence Interval is : ______
to ______.