Statistical Analysis of BMI and Physical Activity of Children and Teenagers

Answers of Multiple Choice Questions

Answers
1. c. Median and Interquartile range
2. d. In this sample, the average BMI of the children is 20.27 kg/m2, with a standard deviation of
3.67 kg/m2.
3. iii. No, variable BMIT already has a Normal distribution
Figure 1: Box Plot of BMIT Shows that the Variable is Normal

Table 1: Descriptive Values for BMIT Shows Slight Positive Skewness
Descriptive
Statistic Std.
Error
Mean 24.2157 .57690
95% Confidence Interval for Mean
Lower Bound 23.0625
Upper Bound 25.3689
5% Trimmed Mean 24.1857
Median 23.9100
Variance 20.968
Std. Deviation 4.57904
Minimum 15.36
Maximum 35.77
Range 20.41
Interquartile Range 6.64
Skewness .168 .302
Kurtosis -.481 .595
Table 2: Tests of Normality for BMIT
Kolmogorov-Smirnova Shapiro-Wilk
Statistic df Sig. Statistic df Sig.
BMIT .078 63 .200* .986 63 .686
*. This is a lower bound of the true significance.
a. Lilliefors Significance Correction

Figure 2: Q-Q Plot for BMIT Shows that BMIT is Normal
4. i. Mean and standard deviation. The reason is that variable BMIT has a normal (symmetric)
distribution.
5. IV. 90% of the children in this sample had their BMI ranged from 15.06 (mean-2SD) to 33.37
(mean+2SD) kg/m2
6. IV. Of the children who consumed more than 5000 kJ, more of them also tend to spend more
than 45 minutes playing sports (60%).