
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

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
Where,
Here n = 23 and
Substitute the values in the above formula
Thus, the rejection region is
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?
Chapter 9 Solutions
Fundamentals of Biostatistics
- Please conduct a step by step of these statistical tests on separate sheets of Microsoft Excel. If the calculations in Microsoft Excel are incorrect, the null and alternative hypotheses, as well as the conclusions drawn from them, will be meaningless and will not receive any points. The data for the following questions is provided in Microsoft Excel file on 4 separate sheets. Please conduct these statistical tests on separate sheets of Microsoft Excel. If the calculations in Microsoft Excel are incorrect, the null and alternative hypotheses, as well as the conclusions drawn from them, will be meaningless and will not receive any points. 1. One Sample T-Test: Determine whether the average satisfaction rating of customers for a product is significantly different from a hypothetical mean of 75. (Hints: The null can be about maintaining status-quo or no difference; If your alternative hypothesis is non-directional (e.g., μ≠75), you should use the two-tailed p-value from excel file to…arrow_forwardPlease conduct a step by step of these statistical tests on separate sheets of Microsoft Excel. If the calculations in Microsoft Excel are incorrect, the null and alternative hypotheses, as well as the conclusions drawn from them, will be meaningless and will not receive any points. 1. One Sample T-Test: Determine whether the average satisfaction rating of customers for a product is significantly different from a hypothetical mean of 75. (Hints: The null can be about maintaining status-quo or no difference; If your alternative hypothesis is non-directional (e.g., μ≠75), you should use the two-tailed p-value from excel file to make a decision about rejecting or not rejecting null. If alternative is directional (e.g., μ < 75), you should use the lower-tailed p-value. For alternative hypothesis μ > 75, you should use the upper-tailed p-value.) H0 = H1= Conclusion: The p value from one sample t-test is _______. Since the two-tailed p-value is _______ 2. Two-Sample T-Test:…arrow_forwardPlease conduct a step by step of these statistical tests on separate sheets of Microsoft Excel. If the calculations in Microsoft Excel are incorrect, the null and alternative hypotheses, as well as the conclusions drawn from them, will be meaningless and will not receive any points. What is one sample T-test? Give an example of business application of this test? What is Two-Sample T-Test. Give an example of business application of this test? .What is paired T-test. Give an example of business application of this test? What is one way ANOVA test. Give an example of business application of this test? 1. One Sample T-Test: Determine whether the average satisfaction rating of customers for a product is significantly different from a hypothetical mean of 75. (Hints: The null can be about maintaining status-quo or no difference; If your alternative hypothesis is non-directional (e.g., μ≠75), you should use the two-tailed p-value from excel file to make a decision about rejecting or not…arrow_forward
- The data for the following questions is provided in Microsoft Excel file on 4 separate sheets. Please conduct a step by step of these statistical tests on separate sheets of Microsoft Excel. If the calculations in Microsoft Excel are incorrect, the null and alternative hypotheses, as well as the conclusions drawn from them, will be meaningless and will not receive any points. What is one sample T-test? Give an example of business application of this test? What is Two-Sample T-Test. Give an example of business application of this test? .What is paired T-test. Give an example of business application of this test? What is one way ANOVA test. Give an example of business application of this test? 1. One Sample T-Test: Determine whether the average satisfaction rating of customers for a product is significantly different from a hypothetical mean of 75. (Hints: The null can be about maintaining status-quo or no difference; If your alternative hypothesis is non-directional (e.g., μ≠75), you…arrow_forwardWhat is one sample T-test? Give an example of business application of this test? What is Two-Sample T-Test. Give an example of business application of this test? .What is paired T-test. Give an example of business application of this test? What is one way ANOVA test. Give an example of business application of this test? 1. One Sample T-Test: Determine whether the average satisfaction rating of customers for a product is significantly different from a hypothetical mean of 75. (Hints: The null can be about maintaining status-quo or no difference; If your alternative hypothesis is non-directional (e.g., μ≠75), you should use the two-tailed p-value from excel file to make a decision about rejecting or not rejecting null. If alternative is directional (e.g., μ < 75), you should use the lower-tailed p-value. For alternative hypothesis μ > 75, you should use the upper-tailed p-value.) H0 = H1= Conclusion: The p value from one sample t-test is _______. Since the two-tailed p-value…arrow_forward4. Dynamic regression (adapted from Q10.4 in Hyndman & Athanasopoulos) This exercise concerns aus_accommodation: the total quarterly takings from accommodation and the room occupancy level for hotels, motels, and guest houses in Australia, between January 1998 and June 2016. Total quarterly takings are in millions of Australian dollars. a. Perform inflation adjustment for Takings (using the CPI column), creating a new column in the tsibble called Adj Takings. b. For each state, fit a dynamic regression model of Adj Takings with seasonal dummy variables, a piecewise linear time trend with one knot at 2008 Q1, and ARIMA errors. c. What model was fitted for the state of Victoria? Does the time series exhibit constant seasonality? d. Check that the residuals of the model in c) look like white noise.arrow_forward
- ce- 216 Answer the following, using the figures and tables from the age versus bone loss data in 2010 Questions 2 and 12: a. For what ages is it reasonable to use the regression line to predict bone loss? b. Interpret the slope in the context of this wolf X problem. y min ball bas oft c. Using the data from the study, can you say that age causes bone loss? srls to sqota bri vo X 1931s aqsini-Y ST.0 0 Isups Iq nsalst ever tom vam noboslios tsb a ti segood insvla villemari aixs-Yediarrow_forward120 110 110 100 90 80 Total Score Scatterplot of Total Score vs. Putts grit bas 70- 20 25 30 35 40 45 50 Puttsarrow_forward10 15 Answer the following, using the figures and tables from the temperature versus coffee sales data from Questions 1 and 11: a. How many coffees should the manager prepare to make if the temperature is 32°F? b. As the temperature drops, how much more coffee will consumers purchase?ov (Hint: Use the slope.) 21 bru sug c. For what temperature values does the voy marw regression line make the best predictions? al X al 1090391-Yrit,vewolf 30-X Inlog arts bauoxs 268 PART 4 Statistical Studies and the Hunt forarrow_forward
- 18 Using the results from the rainfall versus corn production data in Question 14, answer DOV 15 the following: a. Find and interpret the slope in the con- text of this problem. 79 b. Find the Y-intercept in the context of this problem. alb to sig c. Can the Y-intercept be interpreted here? (.ob or grinisiques xs as 101 gniwollol edt 958 orb sz) asiques sich ed: flow wo PEMAIarrow_forwardVariable Total score (Y) Putts hit (X) Mean. 93.900 35.780 Standard Deviation 7.717 4.554 Correlation 0.896arrow_forward17 Referring to the figures and tables from the golf data in Questions 3 and 13, what hap- pens as you keep increasing X? Does Y increase forever? Explain. comis word ே om zol 6 svari woy wol visy alto su and vibed si s'ablow it bas akiog vino b tad) beil Bopara Aon csu How wod griz -do 30 義arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin HarcourtCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL




