statistics power point presentation

ST3004 COMPETENCY ASSESSMENT TEMPLATE
The following table summarizes the different hypothesis test distributions and when each is used. Use this table when completing this
Assessment.
Test
Z Test
t Test
Chi Square
ANOVA
Which Statistical Test Do I Use?
Requirement
Normal distribution
Population mean known
Population standard deviation known
Sample size is greater than 30 if not normal
Quantitative variables
Normal distribution
Population mean known
Population standard deviation unknown
Sample size is a) nearly normal with sample less than
15; b) at least 15 with no outliers; c) greater than 30
even if skewed or not normal
Quantitative variables
Variables are qualitative
Testing if observed results agree with claimed
(Goodness of Fit Unequal Frequencies)
Testing if outcomes occur with the same frequency
(Goodness of Fit Equal Frequencies)
Testing if outcomes are independent of treatment
(Goodness of Fit Test of Independence)
Used to test the relationship between variables
Data in two-way table of counts of outcomes
Compares whether several populations have the same
mean
ST3004 COMPETENCY ASSESSMENT TEMPLATE
Scenario 1: Presidential Ratings
College students are asked to rate two presidential candidates, Mr. Smith and Ms. Jones on how trustworthy their faces appear. The
scale was zero to seven with zero being not at all trustworthy and seven being extremely trustworthy. Below are 29 ratings. Is there
significant evidence at the 5% level that the mean rating is greater than 3.5 (a neutral rating)? Assume that this is a simple random
sample of all U.S. college students.
2.6 3.2 4.7 3.3 3.4 3.6 3.7 3.9 3.9 4.1
4.2 4.9 5.7 4.2 3.9 3.2 4.1 5.0 5.0 4.6
4.6 3.9 3.9 2.8 2.6 3.0 3.3 3.7 5.3
Which type of test would you
use, and why?
State the null and alternative
hypothesis.
Use Statdisk to solve the
Write a conclusion
problem describing the steps statement.
that you used (options in
Statdisk) and paste your
results here.
ST3004 COMPETENCY ASSESSMENT TEMPLATE
Scenario 2: Weekly Births
Are births evenly distributed across the days of the week? A sample of 700 birth days was collected with the following results.
Day
Births
Sun.
84
Mon.
110
Tues.
124
Wed.
104
Thur.
94
Fri.
112
Sat.
72
Test the hypothesis that the births are equally distributed across the days of the week using an alpha of 0.05.
Which type of test would you
use, and why?
State the null and alternative
hypothesis.
Use Statdisk to solve the
Write a conclusion
problem describing the steps statement.
that you used (options in
Statdisk) and paste your
results here.
ST3004 COMPETENCY ASSESSMENT TEMPLATE
Scenario 3: Nursing Job Satisfaction and Retention
A nursing magazine reported the results of a survey of more than 1800 nurses from across the country on job satisfaction and
retention. Nurses from magnet hospitals (an award given by the American Nurses Credentialing Center to hospitals that satisfy a
certain level of criteria designed to measure the strength and quality of nursing) describe staffing as follows:
Staffing Situation
Short of help—patient care has suffered
Short of help—patient care hasn’t suffered
Adequate
More than adequate
Excellent
A survey of 500 nurses from non-magnet hospitals gave the following results.
Staffing Situation
Short of help—patient care has suffered
Short of help—patient care hasn’t suffered
Adequate
More than adequate
Excellent
Percent
12
32
38
12
6
Number
165
140
125
50
20
Determine if the data indicates that the nurses from the non-magnet hospitals have a different distribution of opinions.
Use α = 0.05.
Which type of test would you
use, and why?
State the null and alternative
hypothesis.
Use Statdisk to solve the
Write a conclusion
problem describing the steps statement.
that you used (options in
Statdisk) and paste your
results below.
ST3004 COMPETENCY ASSESSMENT TEMPLATE
Scenario 4: Drug Effectiveness
To test the effectiveness of a new drug, a researcher gives one group of individuals the new drug and another group a placebo. The
results of the study are shown below. At the 0.01 level of significance, can the researcher conclude that the drug is effective? In other
words, are the results independent of the method of treatment?
Medication
Drug
Placebo
Which type of test would you
use, and why?
Effective
32
12
State the null and alternative
hypothesis.
Not Effective
9
18
Use Statdisk to solve the
Write a conclusion
problem describing the steps statement.
that you used (options in
Statdisk) and paste your
results here.
ST3004 COMPETENCY ASSESSMENT TEMPLATE
Scenario 5: Sodium Content
The amount of sodium (in milligrams) in one serving for a random sample of three different foods is listed in the table below. At the
0.10 level of significance, is there sufficient evidence to conclude that a difference in mean sodium amounts exists among the
condiments, cereals, and desserts?
Condiments
270
130
230
180
80
70
200
Which type of test would you
use, and why?
Cereal
260
220
290
290
200
320
140
State the null and alternative
hypothesis.
Desserts
100
180
250
250
300
360
300
Use Statdisk to solve the
Write a conclusion
problem describing the steps statement.
that you used (options in
Statdisk) and paste your
results here.
ST3004 Instruction