Fundamentals of Biostatistics
Fundamentals of Biostatistics
8th Edition
ISBN: 9781305268920
Author: Bernard Rosner
Publisher: Cengage Learning
bartleby

Videos

Textbook Question
Book Icon
Chapter 9, Problem 1P

In a study, 28 adults with mild periodontal disease are assessed before and 6 months after implementation of a dental-education program intended to promote better oral hygiene. After 6 months, periodontal status improved in 15 patients, declined in 8, and remained the same in 5.

Assess the impact of the program statistically (use a two-sided test)

Suppose patients are graded on the degree of change in periodontal status on a 7-point scale, with +3 indicating the greatest improvement, 0 indicating no change, and −3 indicating the greatest decline. The data are given in Table 9.9.

Table 9.9 Degree of change in periodontal status

Chapter 9, Problem 1P, In a study, 28 adults with mild periodontal disease are assessed before and 6 months after

Expert Solution & Answer
Check Mark
To determine

Illustrate the impact of the program statistically.

Explanation of Solution

From the given information, the degree of change in periodontal status before and after the oral dental- education program is given. The scores are given on a 7 point scale with +3 indicate greatest improvement, 0 indicate no improvement and -3 indicate the greatest decline.

It is appropriate to use sign test.

Null hypothesis:

H0: The impact of program is not statistically significant.

Alternative hypothesis:

H1: The impact pf program is statistically significant.

Thus, C = 15 and n =15+8 = 23.

Calculation:

There are 15 positive and 8 negative scores. Since 23 > 20, the normal theory test can be used. The rejection region is given as C>c2 or C<c1.

Where,

c2=n2+12+z1α2n4 and c1=n212z1α2n4

Here n = 23 and

 z1α2=z10.052=z10.025=z0.975=1.96using Excel formula "=NORM.S.DIST0.975"

Substitute the values in the above formula

c2=232+12z0.975234=12+1.962.398=12+4.7=16.7

c1=23212z0.975234=111.962.398=114.7=6.3

Thus, the rejection region is c2=16.7 and c1=6.3. Here C=15, 6.31516.7. Thus, fail to reject the null hypothesis at 5% level of significance.

Thus, it can be concluded that patients does not significantly changes on the program. It can be assumed that the periodontal status of patients will remain unchanged in the absence of program, which is a questionable assumption. It is appropriate to use a study design of comparing two groups with a control group over 6 months who did not receive the education program.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Q.2.4 There are twelve (12) teams participating in a pub quiz. What is the probability of correctly predicting the top three teams at the end of the competition, in the correct order? Give your final answer as a fraction in its simplest form.
The table below indicates the number of years of experience of a sample of employees who work on a particular production line and the corresponding number of units of a good that each employee produced last month. Years of Experience (x) Number of Goods (y) 11 63 5 57 1 48 4 54 5 45 3 51 Q.1.1 By completing the table below and then applying the relevant formulae, determine the line of best fit for this bivariate data set.  Do NOT change the units for the variables.   X y X2 xy         Ex= Ey= EX2 EXY= Q.1.2 Estimate the number of units of the good that would have been produced last month by an employee with 8 years of experience.   Q.1.3 Using your calculator, determine the coefficient of correlation for the data set. Interpret your answer. Q.1.4 Compute the coefficient of determination for the data set. Interpret your answer.
Can you answer this question for me
Knowledge Booster
Background pattern image
Statistics
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Text book image
Big Ideas Math A Bridge To Success Algebra 1: Stu...
Algebra
ISBN:9781680331141
Author:HOUGHTON MIFFLIN HARCOURT
Publisher:Houghton Mifflin Harcourt
Text book image
College Algebra (MindTap Course List)
Algebra
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:Cengage Learning
Text book image
College Algebra
Algebra
ISBN:9781938168383
Author:Jay Abramson
Publisher:OpenStax
Text book image
Holt Mcdougal Larson Pre-algebra: Student Edition...
Algebra
ISBN:9780547587776
Author:HOLT MCDOUGAL
Publisher:HOLT MCDOUGAL
Hypothesis Testing using Confidence Interval Approach; Author: BUM2413 Applied Statistics UMP;https://www.youtube.com/watch?v=Hq1l3e9pLyY;License: Standard YouTube License, CC-BY
Hypothesis Testing - Difference of Two Means - Student's -Distribution & Normal Distribution; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=UcZwyzwWU7o;License: Standard Youtube License