Question

Because elderly people may have difficulty standing to have their heights measured, a study looked at predicting overall height from the height to the knee. The data (in cm) for five elderly men is as follows:

Knee Height, x	57.7	47.4	43.5	44.8	55.2
Overall Height, y	192.1	153.3	146.4	162.7	169.1

1. Mean of Knee Height, x and Overall Height, y.

2. Variance of Knee Height, x and Overall Height, y.

3. Standard deviation of Knee Height, x and Overall Height, y?

Show your R-codes and output/result (copy/paste) in the spaces for this question.

Answer 1

R codes

First create a data vector for knee height and overall height. Here, x is the object name for knee height and y is the object name for overall height. R codes to compute mean. variance and standard deviation is mean(), var() and sd(), respectively.

The output is reported just after the command.

x=c(57.7,47.4,43.5,44.8,55.2)
y=c(192.1,153.3,146.4,162.7,169.1)

mean(x)
[1] 49.72

mean(y)
[1] 164.72

var(x)
[1] 40.497

var(y)
309.742

sd(x)
6.363725

sd(y)
17.59949