WY5V8181
HR

(a) 

public double getCompoundAvg(String comp){
    int ct = 0;
    double totalTemp = 0;
    for (Trial trial : trialList){
        if (trial.getCompound() != comp) continue;
        ct++;
        totalTemp += trial.getTemp();
    }
    if (ct > 0) return totalTemp/ct;
    else return -1;
}

(b)

public String getCompoundWithHighestAvg(){
    double max = -1; // less than all non-negative temperatures.
    String compound;
    for (String curCompound : getCompoundList()){
        double avg = getCompoundAvg(curCompound);
        if (avg > max){
            max = avg;
            compound = curCompound;
        }
    }
    return compound;
}

(c)

The programmer would need to add the amount of compound used as a
private instance variable (with a getter) in Trial (which would be
initialized in its constructor). ScienceExperiment would hold the method
`public double getCompoundAmountUsed(String compoundName)` which would
sum, for all Trials in trialList with the same compoundName as given,
the value of trial.getAmountUsed(), and return that value.