(a) Before doing the hypotheses testing, let's first compute some descriptive statis- tics and visualize the data using graphs. What are the sample means and sample standard deviation for each of the conditions? Use hist() function to graph the frequency distribution for the sample data in each condition. Which condition gen- erally took the participants longer to complete? Attach the graphs and R code. (b) Which one is a more appropriate test for this data set, paired sample t-test or independent-samples t-test? Explain. (c) State the null and alternative hypotheses. Assume that we are doing a directional test.
(a) Before doing the hypotheses testing, let's first compute some descriptive statis- tics and visualize the data using graphs. What are the sample means and sample standard deviation for each of the conditions? Use hist() function to graph the frequency distribution for the sample data in each condition. Which condition gen- erally took the participants longer to complete? Attach the graphs and R code. (b) Which one is a more appropriate test for this data set, paired sample t-test or independent-samples t-test? Explain. (c) State the null and alternative hypotheses. Assume that we are doing a directional test.
MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
Related questions
Question
Transcribed Image Text:In a Stroop test, participants are presented with a list of color words, with
each word displayed in an ink color. The participant's task is to say out loud the ink color
in which the word is printed. The task has two conditions: a congruent words condition,
and an incongruent words condition. In the congruent condition, the color of the word
matches the spelling of the printed word; but in the incongruent condition, the color
of the word does not match the spelling of the printed word. Each participant usually
participates in both conditions. I have uploaded a Stroop test dataset of 24 participants
the file name being stroopdata.csv. The dataset shows
the time (in seconds) it took for each participant to complete the task in each condition.
In this question, you will need to conduct the appropriate t-test for this dataset.
(a) Before doing the hypotheses testing, let's first compute some descriptive statis-
tics and visualize the data using graphs. What are the sample means and sample
standard deviation for each of the conditions? Use hist() function to graph the
frequency distribution for the sample data in each condition. Which condition gen-
erally took the participants longer to complete? Attach the graphs and R. code.
(b) Which one is a more appropriate test for this data set, paired sample t-test or
independent-samples t-test? Explain.
(c) State the null and alternative hypotheses. Assume that we are doing a directional
test.
(d) Compute the t-statistic for our sample data. Show work. Attach R code if used.
(e) Over repeated samples, which distribution does the t-statistic follow assuming Ho
is true? (Hint: include the degrees of freedom).
(f) Compute the p-value. Show work and attach R code.
(g) How do you interpret the p-value?
(h) Suppose a = 0.05. Can you reject the null? What is your conclusion?
(i) Using the same a level, compute the upper critical t-value. What is the upper
critical t-value? Based on the upper critical t-value, can you reject the null? Attach
R code.
(j) Use t.test function conduct the t-test. Do you obtain the same p-value? Attach
the code.
Transcribed Image Text:Congruent Incongruent
12.079
16.791
9.564
8.630
14.669
12.238
14.692
8.987
9.401
14.480
22.328
15.298
15.073
16.929
18.200
12.130
18.495
10.639
11.344
12.369
12.944
14.233
19.710
16.004
19.278
18.741
21.214
15.687
22.803
20.878
24.572
17.394
20.762
26.282
24.524
18.644
17.510
20.330
35.255
22.158
25.139
20.429
17.425
34.288
23.894
17.960
22.058
21.157
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