Biostatistics Assignment 2

401077 Introduction to Biostatistics, Autumn 2019
Assignment 2
Due Sunday September 15, 2019
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Question 1
a) The 95% confidence interval of mean grip strength is (31.35763,
32.36045). With 95% confidence, the true mean of grip strength lies between
31.35763 and 32.36045.
b) The 95% confidence interval of mean grip strength confirms that the mean
value is not significantly equal to 33 kgs at the 0.05 significance level.
The mean of grip strength that is 33 kgs does not lie between 31.35763
and 32.36045 hence it value is not significantly equal to 33 kgs at the 0.05
significance level.

c) The Null Hypothesis (H0): There exists a difference between male and
female mean grip strength.
Alternative Hypothesis (HA): There does not exist a difference between male
and female mean grip strength.
The Significance Level: The significance level is set at 0.05.
The Test Statistic and Corresponding P-Value: The male and female mean
grip strength is 31.60399 and 32.11191 respectively. Now, the estimated t-stat is
-0.99822 with 0.3192 p-value that is greater than 0.05 (Heimann
et al., 2019).
The p-value suggests not to reject the null hypothesis.
Conclusion: The mean grip strength does not differ between male and female.
d) The Null Hypothesis (H0): There is no shift in location.
Alternative Hypothesis (HA): There is no shift in location.
The Significance Level: The significance level is set at 0.05.
The Test Statistic and Corresponding P-Value: w-stat is 6418 with 0.475 p-
value which is greater than 0.05. The p-value suggests to retain the null
hypothesis.
Drawing a Conclusion: The location shift is equal to zero.
Question 2
a) The Null Hypothesis (H0): The proportion of grandparent carers with
hypertension is not greater than 0.25.
Alternative Hypothesis (HA): The proportion of grandparent carers with
hypertension is greater than 0.25.
The Significance Level: The significance level is set at 0.05.
The Test Statistic and Corresponding P-Value: The χ2 stat is 2.4049 with 1
df (Pagano & Gauvreau, 2018). The p-value is 0.06048 greater than 0.05. Hence,
the null hypothesis is retained.
Drawing a Conclusion: The proportion of grandparent carers with hypertension
is not greater than 0.25.
b) The 95% confidence interval of the difference between male and
female proportion with hypertension is (0.03286422, 0.09589114). The