Goodness of fit
χ2 goodness of fit test
We can use the χ2 goodness of fit test to decide if a set of observations fit a particular, expected distribution.
H0: The data fits an expected distribution
HA: The data does not fit an expected distribution
Goodness of fit
We can use the χ2 goodness of fit test to decide if a set of observations fit a particular, expected distribution.
H0: The data fits an expected distribution
HA: The data does not fit an expected distribution
| # Example chi-square | |
| chi_square <- ((50 – 56.25)^2 / 56.25) + | |
| ((20 – 18.75)^2 / 18.75) + | |
| ((20 – 18.75)^2 / 18.75) + | |
| ((10 – 6.25)^2 / 6.25) | |
| print(chi_square) | |
| ## Chi-square distribution | |
| pchisq(3.11, df = 3, lower.tail = FALSE) | |
| ## Check to our results | |
| obs <- c(50, 20, 20, 10) | |
| expect_prob <- c(9 / 16, 3 / 16, 3 / 16, 1 / 16) | |
| chisq.test(obs, p = expect_prob) |