### R F-test Example

`var.test()`

function performs F-test between 2 normal populations with hypothesis that variances of the 2 populations are equal.

var.test(x, ...) var.test(x, y, ratio = 1, alternative = c("two.sided", "less", "greater"), conf.level = 0.95, ...)

`x,y`

: Normally distributed data sets`ratio`

: Hypothesized ratio of x/y, default is 1`alternative`

: alternative hypothesis, including "two.sided","greater","less"`conf.level`

: confidence level`...`

> x <- rnorm(100, mean=0) > y <- rnorm(100, mean=1) > var.text(x,y)

F test to compare two variances data: x and y F = 0.8795, num df = 99, denom df = 99, p-value = 0.5242 alternative hypothesis: true ratio of variances is not equal to 1 95 percent confidence interval: 0.5917706 1.3071567 sample estimates: ratio of variances 0.8795095

Since the p-value = 0.5242, which is much higher than 0.05, the hypothesis that the variances of x and y are equal is accepted.