Statistics - Hypothesis Testing Projects

SPSS Exercise 6 One Sample t -test It is the year 2074 and the wind is blowing strongly across the red

SPSS Exercise 6

One Sample t -test

It is the year 2074 and the wind is blowing strongly across the red sand of Mars. The human colony has been on Mars for 20 years. The original colony of 1000 adults left earth in the first phase of the Mars Exploration Project. Since that time the colony has prospered and grown. The plight of Earth remains unknown. The colony commanders lost contact a few weeks after take off and all water on Earth seems to have disappeared. The Behavioral Science Unit (B.S.U) has noticed that the children born on Mars in 2058 appear to be a particularly intelligent group. The B.S.U. has data from the original population from earth and wants to compare the IQ's of this sample with the population.

The B.S.U gave the 30 children born on Mars in 2058 the Wechsler Intelligence Test and obtained the following scores:

IQ Score	IQ Score	IQ Score
115	115	111
110	110	118
140	102	97
135	103	95
160	119	100
127	121	160
139	125	99
140	127	101
100	130	102
115	103	104

The population that colonized Mars had an IQ average of 109

Open SPSS and enter the data for the sample in a new spreadsheet using the name MarsIQ for the variable name. After the variables are named and the data are entered, calculate the descriptive statistics for the sample ( Analyze, Descriptive Statistics, Frequencies ), Move MarsIQ to the right box, click on Statistics, check the boxes as in the previous assignments, click on continue and then OK. Now carry out the one sample t-test by selecting Analyze, Compare Means, One sample t -test .

Move MarsIQ to the test variable box. In the box labeled Test Value you need to enter the population mean and then click OK. After completing this task, conduct another one sample t -test using 0 in the Test Value box so that you can compare the confidence intervals.

Next select Graphs (legacy) then Boxplot and click on simple . Place a mark in the circle by summaries for separate variables and then click d efine . Select MarsIQ and move the variable to the Boxes Represent window. Click OK.

Write the null and alternative hypotheses

H 0:

H 1:

From your output identify/complete the following:

the test value (population mean) for this problem __________
the mean IQ score for the children born in 2058 __________
t -test value for the one-sample t -test using the test value in the analysis __________
p value for the one-sample t -test using the test value (population mean) in the analysis __________

Is there a difference between the population and the sample? Explain your findings

SPSS Exercise 7

Independent t -test

The psychology department at Jones University wants to determine if a workbook will improve the performance of the students in the Psychology classes rather than additional assignments. Students were randomly selected from the lecture session and one group was given a workbook to use and a second group was given additional reading assignments. Open SPSS and enter the data. In order to enter data for the independent t -test, you must have a column for experimental condition (the independent variable) AND a column for the scores (dependent variable). When you are entering the variables in the Variable view window, name the variable in row 1 "conditions" (the independent variable) and then tab over to the labels column and enter 1 = workbook 2 = assignments. Name the next row "score" and then tab over to label and enter the variable name (score) in the label cell.

In doing this you will be able to enter the numbers 1 and 2 in your data window for the conditions and the labels will show on your output. (The alternative is to enter conditions as a string variable and then type in workbook or assignment for each person). Therefore, the data are not entered as it would be if you were doing the hand calculation. Click on the Data View tab at the bottom of the screen and begin to enter your data. Make sure that you match up the condition in column 1 with the right score in column 2.

Once you have your data entered, click on Analyze, Compare Means, Independent Samples t -test . In the dialog box, select conditions for the grouping variable (conditions) and scores for the Test variable. Next you need to click on Define and define for the computer what your grouping variables are. Enter 1 for group 1 and 2 for group 2. Click OK to complete the analysis.

The following data are from the unit test.

Workbook group	Assignment group (2)
89	78
84	79
66	72
74	85
78	66
85	62
97	58
95	71
61	70
82	80
84	90
86	85
84	55
79	74
72	78
85	79
88	74
90	76
59	77
84	72
79	75
75	71
72
74
75

Before submitting your work complete the questions below by entering the numbers from the output file.

What are the means for each of the conditions?

Workbook group __________
Assignment group __________

What are the standard deviations for each of the conditions?

Workbook group __________
Assignment group __________

What are the t value, df , and significance level (equal variances assumed)?

t -test value __________
df __________

significance level __________

Are the results significant (set  = .05) Yes No
Is there a difference between the groups? Explain your findings

SPSS Exercise 8

Paired-Samples t -Test

Research has shown that a liberal arts education "liberalizes" the student's viewpoints. The college wants to know if the Nursing program has such an effect. Mother's who have not had a college education are paired with their daughter's who have just completed the Nursing program. A previous test had shown that there were no differences between the groups prior to the Nursing program. Both mothers and daughters complete the "Modern Liberality Inventory" (MLI).

Open SPSS and enter the data from the table below. Notice that since this is a paired-samples t -test that the data are entered in two columns with each column being one of the variables (mother and daughter) (see Figure 2). Select " Analyze " and then select " Compare Means ". Select the " Paired Samples t -test " option. When the dialog box appears move the names of the two variables that you want to compare from the left box to the right side. Click OK.

Now create a scatterplot. Select " Graphs " (legacy) from the menu bar and then select "scatter" Click on the simple box and then "define". Select ‘mother’ for the X-axis and ‘daughter’ for the Y-axis. Click OK.

Case number	Mother	Daughter	Case number	Mother	Daughter
1	89	53	16	95	76
2	91	62	17	89	84
3	84	75	18	56	89
4	89	75	19	85	56
5	89	82	20	81	72
6	75	89	21	82	62
7	89	64	22	87	95
8	75	75	23	85	75
9	79	83	24	95	86
10	82	84	25	86	75
11	82	89	26	84	67
12	75	89	27	82	69
13	89	85	28	85	70
14	94	91	29	89	89
15	92	81	30	75	94

Write the null and alternative hypotheses:
H O:
H 1:
From the output:
1. What is the mean for the Mother’s score? __________
  (2) What is the standard deviation for the Daughter’s score? __________
  (3) What is the t test result? __________
  (4) What is the significance level ( p ) of the test? __________
Are the findings significant?
Briefly explain the results. Does a liberal arts education, "liberalize" a students’ viewpoints?