Question

Please use R and R studio

A sample of 15 female collegiate golfers was selected and the clubhead velocity (km/hr) while swinging a driver was determined for each one, resulting in the following data (“Hip Rotational Velocities During the Full Golf Swing,” J.of Sports Science and Medicine, 2009: 296–299):

69.0 69.7 72.7 80.3 81.0

85.0 86.0 86.3 86.7 87.7

89.3 90.7 91.0 92.5 93.0

The corresponding z percentiles are

-1.83 -1.28 -0.97 -0.73 -0.52

-0.34 -0.17 0.0 0.17 0.34

0.52 0.73 0.97 1.28 1.83

Construct a normal probability plot and a dotplot. Is it plausible that the population distribution is normal?

Answer 1

Please use R and R studio

A sample of 15 female collegiate golfers was selected and the clubhead velocity (km/hr) while swinging a driver was determined for each one, resulting in the following data (“Hip Rotational Velocities During the Full Golf Swing,” J.of Sports Science and Medicine, 2009: 296–299):

69.0 69.7 72.7 80.3 81.0 85.0 86.0 86.3 86.7 87.7 89.3 90.7 91.0 92.5 93.0

The corresponding z percentiles are

-1.83 -1.28 -0.97 -0.73 -0.52

-0.34 -0.17 0.0 0.17 0.34

0.52 0.73 0.97 1.28 1.83

Construct a normal probability plot and a dotplot. Is it plausible that the population distribution is normal?

R commands:

velocity =c(69.0, 69.7, 72.7, 80.3, 81.0, 85.0, 86.0, 86.3, 86.7, 87.7, 89.3, 90.7, 91.0, 92.5, 93.0)

qqnorm(velocity)

qqline(velocity)

dotchart(velocity)

The normal plot shows that data points are not in straight pattern. This shows that are not normally distributed.

The dot plot shows the data are negatively skewed.