Answer:
1. Amount of rain is the explanatory variable and yield of corn is the response variable.
Step-by-step explanation:
Explanatory Variable is the causal variable, which effects the other variable.
Response Variable is the resultant variable, which is effected by the other variable.
In this case, amount of rain effects the yield of corn (bushels per acre).
So, Amount of rain being causal effecting variable - is Explanatory Variable. Corn yield, being resultantly effected variable - is Response Variable.