34.7 Quick review questions

A study of Chinese paedatric patients (Wong et al. 2018) studied the relationship between the 6-minute walk distance (6MWD) and maximum oxygen uptake (VO2_max) for \(n= 2 9\) patients. The correlation coefficient is reported as \(r = 0.457\), and the corresponding \(P\)-value as \(P = 0.013\).

1. The \(x\)-variable is
   6-minute walk distance Maximum oxygen uptake
2. True or false: Since the \(P\)-value is small, the correlation must be quite strong.
   TRUE FALSE
3. The relationship is best described as
   Negative Positive
4. The value of \(R^2\) (to one decimal place, expressed as a percentage) is:
   
5. For statistical validity, we need to assume that:
   The response variable has a normal distribution The explanatory variable has a normal distribution The sample size is larger than 25 A linear relationship exists between the variables

References

Wong P-F, Chan EY-T, Ng DK-K, Kwok K-L, Yip AY-F, Leung S-Y. Correlation between 6-min walk test and cardiopulmonary exercise test in Chinese patients. Pediatric Respirology and Critical Care Medicine. Medknow Publications; 2018;2(2):32.

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Peter K. Dunn, 2021: CC BY-NC-SA 4.0