Question

The following table gives the yields on 15 sample plots under three 

varieties of seed:

A 20 21 23 16 20

B 18 20 17 15 25

C 25 28 22 18 32

Find out whether the average yield of land under different varieties of 

seed show significant differences.

Answer 1

We will carry out an ANOVA test, assuming the samples were normally distributed and the variances in the three populations were homogeneous. He selected Anova: Single Factor, then entered the data ranges, selected Grouped By: Rows and set Alpha to 0.05. He selected a suitable output option and then OK.

The F value calculated was 3.1. This is less than the stated critical value (F crit ) of 3.8852, and the probability of obtaining this result by chance (P-value) was calculated as 0.08215976 (8.21% to three significant figures). We conclude that there was not a significant difference in average yield of land under different varieties of seed, since P >0.05.