Statistics: Analysis and Results

Statistics
Statistics
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Statistics
Introduction
A survey was conducted with the main objective being to determine the extent of risk that a
population was to getting kidney disease. Since hypertension is one of the major risks of getting
kidney disease, a sample of 30 was sample and their systolic blood pressure measured and
recorded. A simple random sampling method was employed to sample 15 males and 15 females.
However, this sampling method has some bias but less compared to other methods of sampling.
One of the biases occurs when the sample obtained is not inclusive of the larger population. The
study claims that the mean systolic BP is 127 for the population.
Data analysis and results
The mean and standard deviation of systolic BP
DESCRIPTIVE STATISTICS
Mean 124.7666667
Median 123.5
Standard Deviation 9.031299343
Table 1
From the table above, it can be observed that the mean systolic BP is 124.76 mmHg. The
standard deviation is 9.03 mmHg.
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Statistics
95% confidence interval for the mean
Confidence Level(95.0%) 3.372343
Mean 124.7667
Lower bound 121.3943
Upper bound 128.139
Table 2
The 95% confidence interval values are as shown in table 2 above. It can be concluded that 95%
of the times, we are confident the mean systolic BP will always lie between 121.77 mmHg and
128.14 mmHg.
One sample t-test
Hypothesis
H0: Mean systolic BP = 127mmHg
H1: Mean systolic BP ≠ 127mmHg
t-Test: Two-Sample Assuming
Unequal Variances
Variable 1 Variable 2
Mean 124.766667 127
Variance 81.5643678 0
Observations 30 30
Hypothesized Mean Difference 0
df 29
t Stat -1.354453
P(T<=t) one-tail 0.09302588
t Critical one-tail 1.69912703
P(T<=t) two-tail 0.18605176
t Critical two-tail 2.04522964
Table 3
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