INSTRUCTIONS:
ANSWER ALL QUESTIONS
PRODUCE YOUR SOLUTIONS AS A WORD DOCUMENT
DUE DATE: 27TH NOVEMBER 2021
Question one
a) Schematically depict operational definition of the concept of
household/community sanitation levels and state 10 questions that will
measure community sanitation. (30 marks)
b) Explain how each of the questions in (1) above could help measure the
concept of community sanitation considering the dimensions and the
elements. (20 marks)
Hint: You may support your answers with appropriate references
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Question two
A study has 20 subjects, all males between the ages 25 and 35 who volunteer for the
experiment. One half of the group was given coffee containing caffeine; the other
half was given decaffeinated coffee as the placebo (control). The pulse rate was
measured after the subjects drink their coffee. The results are:
Placebo Caffeine
72 76
76 80
66 78
68 84
68 72
74 66
60 68
64 76
72 76
60 74
(a) Test the hypothesis that caffeine has no effect on the pulse rates of young
men at 99% confidence level. (12 marks)
(b) Find the 90% C.I. for the population mean difference. Interpret your results.
(4 marks)
(c) State any four (4) assumptions required for the above problem. (4 marks)
Question three
Suppose a researcher is interested in estimating the proportion of stunted children
aged below 5 years in a given population/community. From a previous study, the
stunting prevalence is 18%. The researcher needs to calculate the sample size with
a precision level of 4% and type 1 error (level of significance) of 5%. Calculate the
required sample size for this study. (10 marks)
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Question four (4)
A researcher wants to know the average systolic blood pressure among women
attending antenatal clinic at Korle-Bu Teaching Hospital in Accra. From a previous
study, the standard deviation is 25mmHg. The researcher needs to calculate the
sample size with a precision level of 5mmHg and type 1 error (level of significance)
of 5%. What is the required sample size for this study? (10 marks)
Question five (5)
Researchers at the University of Ghana School of Public Health want to know the
link between lung cancer and exposure to smoking among adults aged 18-45 years
and proposed to use a power of 80% with expected proportion in cases and controls
to be 0.39 and 0.12 respectively based on a previous study, 5% type 1 error and to
have equal number of cases and controls. Estimate an appropriate sample size for
their study. (10 marks)