Question

3. An agronomist is trying a variety of fertilizer treatments on different parcels of land. The goal is to see how sod yield changes and whether or not there is a difference across fertilizers. The numbers below are sod yields in square yards.

                                                            Fertilizer Treatment

                                    Qtr Dose Wkly          Half Dose (2 wks)    Full Dose (4 wks)

Parcel A                                 77                                83                                80

Parcel B                                 79                                91                                82

Parcel C                                 87                                94                                86

Parcel D                                 85                                88                                85

Parcel E                                 78                                85 80

test to see if there is a difference in the average yields across the different fertilizer treatments. Use the p-value method. Use alpha = 0.01

Answer 1

To test against H₁ : at least one mean is different.

Using Minitab software, (Stat -> ANOVA -> One way), we get the following output :

Since p-value = 0.039 > 0.01, so we fail to reject H₀ at 1% level of significance and we can conclude that there is significant difference in the average yields across the different fertilizer treatments.