An agronomist undertook an experiment to investigate the factors that potato harvest. In his research, agronomist decided to divide the farm into 30 half hectare plots and apply varies level of fertilizer. Potato was then planted and the harvest at the end of the season was recorded.

Fertilizer(Kg)	Harvest (tons)
210	43.5
220	40.0
230	48.0
240	65.0
250	80.0
260	85.0
270	95.0
280	80.0
290	97.3

Note: No excel ANOVA output allowed. please show calculation in steps

1. Find the simple regression line and interpret the coefficients.

2.Find the coefficient of determination and interpret its value.

3.Does the model appear to be a useful tool in predicting the potato harvest? If so, predict the harvest when 250KG of fertilizer is applied. If not explain why not.