Assignment on Fundamentals of Applied Statistics

Final Exam Week 8
Chapters 1-12
44 questions, 200 points
Place answers here
1.D 23.True
2.C 24.True
3.D 25.False
4.C 26.True
5.B 27.False
6.B 28. C.I =[27.93,35.40]
7.A 29.35
8.D 30. S.D=5.883
9.D 31. The value of z is -20.27 The value of p is < .00001. The result is significant at p < .05
10.True 32. P>.05 hence not statistically significant.There is there no statistical evidence of a lower mean PEF in
children with chronic bronchitis at alpha=.05
11.True 33. Conclusion:Since the p-value is less than 5%, reject Ho.There is a statistical difference in the proportions.
12.False 34. C.I =[-13.056, -3.744]
13.True 35. Yes. p<.05 hence there is a significant difference among the treatments at alpha=.05
14.True 36. The result is not significant at alpha=.05 since p > .05.
15.True 37. The value of z is -1.4676. The value of p is .14156. The result is not significant at p < .05.
16.True 38.
Source of Variation SS df MS F
Between Groups 1524.4 3 508.133 2.186
Within Groups 3719.48 16 232.468
Total 5,243.88 19
P=.129
17.False 39. No.There is no significant increase in body weight following supplementation t(5)=-
0.5,p>.05
18.True 40. p-value equals 0.1797, Since p-value > α, H0 is accepted. There is therefore no significant
difference in self-reported improvement in pain
19.False 41. No.There is no statistical significant difference (p>.05) in the characteristics shown among the
treatments .The age, female and annual income.
However significant differences were observed in insurance and disease stage (p<.05)
20.False 42. Chi-square test
21.False 43. Mean 1196.25
Standard deviation=1806.828
Median=580
First Quartile=427.5

Third Quartile=825
22.False 44. No.There is no statistical significant difference (p>.05) in the mean age,highschool education and Systolic
Blood Pressure between the placebo and experimental group.
Multiple Choice
1. Which of the following individuals is likely to be excluded from a clinical trial?
A) An individual with other diseases besides the disease of interest.
B) An individual whose data is considered to be an outlier.
C) An individual of who is considered to be a minority.
D) An individual who will have difficulty complying trial protocols.
2. Randomization in a clinical trial is defined as which of the following?
A) The process by which individuals are coupled into groups for comparison in order to minimize bias and
confounding.
B) The process by which individuals are assigned a number and are selected through the usage of a pattern which
minimizes bias and confounding.
C) The process by which individuals are randomly assigned to a treatment or control group which minimizes bias
and confounding.
D) The process by which individuals are asked to volunteer for a study which minimizes bias and confounding.
3. Assuming 50,000 individuals in the United States are diagnosed every year, and of those individuals diagnosed
with HIV each year, approximately 33,500 individuals diagnosed with HIV are gay or bisexual males. What
prevalence of the new HIV cases are from members of the population of gay or bisexual males?
A) 0.67%
B) 6.70%
C) 33.0%
D) 67.0%
4. Ethnicity is best described as which type of variable?
A) Dichotomous variable
B) Ordinal variable
C) Categorical variable
D) Continuous variable
5. A researcher wants to determine the sensitivity of mammograms to determine how effective they are at
diagnosing women who have breast cancer. Assume the researcher obtained the above results from a study, calculate
and interpret the sensitivity of mammograms for detecting breast cancer.
Frequency of Breast Cancer Cases Frequency of Non-Cancer Cases

Frequency of Individuals Who
Screened Positive 17 5
Frequency of Individuals Who
Screened Negative 8 77
A) A total of 66.67% of individuals who have breast cancer test positive for breast cancer when using a
mammogram as the primary diagnostic test for breast cancer.
B) A total of 68% of individuals who have breast cancer test positive for breast cancer when using a mammogram as
the primary diagnostic test for breast cancer.
C) A total of 70.59% of individuals who have breast cancer test positive for breast cancer when using a
mammogram as the primary diagnostic test for breast cancer.
D) A total of 92.77% of individuals who have breast cancer test positive for breast cancer when using a
mammogram as the primary diagnostic test for breast cancer.
6. A researcher wants to compare the mean concentration of two medications considered biologically equivalent,
i.e., two medications that are able to produce the same therapeutic effect at the same level of concentration in the
blood. The group of individuals on medication one (n = 32) had a mean blood concentration of 21.7 micrograms per
milliliter with a standard deviation of 8.7 micrograms per milliliter. The group of individuals on medication two (n =
32) had a mean blood concentration of 19.4 micrograms per milliliter with a standard deviation of 5.2 micrograms
per milliliter. Construct and interpret a 95% confidence interval demonstrating the difference in means for the
individuals on medication one when compared to the group of individuals on medication two.
A) The researchers are 95% confident that the true mean difference in medication concentration levels between
individuals on medication one and individuals on medication two is between 4.867 micrograms per milliliter and
9.467 micrograms per milliliter.
B) The researchers are 95% confident that the true mean difference in medication concentration levels between
individuals on medication one and individuals on medication two is between -1.212 micrograms per milliliter and
5.812 micrograms per milliliter.
C) The researchers are 95% confident that the true mean difference in medication concentration levels between
individuals on medication one and individuals on medication two is between 11.747 micrograms per milliliter and
16.347 micrograms per milliliter.
D) The researchers are 95% confident that the true mean difference in medication concentration levels between
individuals on medication one and individuals on medication two is between 3.477 micrograms per milliliter and
8.077 micrograms per milliliter.
7. A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms
of asthma. Two hundred participants are enrolled in the study and randomized to receive either the
experimental medication or placebo. The primary outcome is self-reported reduction of symptoms.
Among 100 participants who receive the experimental medication, 38 report a reduction of symptoms as
compared to 21 participants of 100 assigned to placebo. When you test if there is a significant difference
in the proportions of participants reporting a reduction of symptoms between the experimental and
placebo groups. Use α = 0.05. What should the researcher’s conclusion be for a 5% significance level?
Reject H0 because 2.64 ≥ 1.960. We have statistically significant evidence at α = 0.05 to show that there is a
difference in the proportions of patients reporting a reduction in symptoms.
A) We reject H0 at the 5% level because 2.64 is greater than 1.96. We do have statistically significant
evidence at α = 0.05 to show that there is a difference in the proportions of patients reporting a reduction in
symptoms.