Introduction to Biostatistics

Introduction to Biostatistics
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ANS: The variable “grip” is a continuous variable as it is participant’s maximum
hand grip strength in measured in kilograms. Weight is always a continuous variable
and so is “grip”.
Figure 1: WHO body mass classification plot
ANS: WHO body mass classification in Figure 1 reveals that majority (N = 126) of
sample participants are overweight, followed by N = 65 obese participants. Only 1
participant is underweight and 41 are noted to have normal BMI. Hence, majority of
the grandparents participating in the present study are suffering from overweight
hazards.
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ANS: As measures of central tendency, average BMI is noted to be 28.30 with
median at 27.79. Median is noted to be less than mean, implying the shape of the
distribution to be slightly right skewed. Spread of BMI range of participants is noted
between 17.73 and 40.83, where participants with their BMI in bottom 25% BMI
range is below 25.84. The top 25% BMI of participants is noted above 30.44.
Table 1: Descriptive Summary table of BMI constructed using from R output
Descriptive
Summary BMI
Min 17.73
1stQu 25.84
Median 27.79
Mean 28.3
3rdQu 30.44
Max 40.83
ANS: The following side by side box plot in Figure 2 demonstrates the “hand grip
strength” by WHO classification of BMI (Hofmann, Wickham, & Kafadar, 2017).
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Figure 2: Side by side box plot for Hand grip strength by BMI
The Side-by-side box plot in Figure 2 aids in comparing essential information about
the hand grip strength of participants. The comparison was possible hand grip
strengths for four different levels of BMI indices. Median values and the range of
hand grip strengths are evident from the Side-by-side box plot. It is important to note
that hand grip strength is higher for underweight and then normal BMI classified
people. Overweight and obese are noted to have less hand grip strength compared to
normal and underweight participants. The shape of the hand grip strength is noted to
be normal in “normal” BMI people, whereas, a slight right skewness can be noted for
overweight grandparents. Obese participants are noted to have highly left skewed
distribution of hand grip strength.
ANS: A scatterplot has been drawn to assess the relation between hand grip strength
and BMI of participants.
Figure 3: Scatterplot for Grip strength on BMI
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