returnVal cannot be resolved to a variable [duplicate]

Here's my code:

public class Result implements IEvent {
    int position;
    double time1;
    double time2;
    double time3;
    double time4;
    int penalties;
    
    public Result (int aPosition, double t1, double t2, double t3, double t4, int thePenalties) {
        this.position = aPosition;
        this.time1 = t1;
        this.time2 = t2;
        this.time3 = t3;
        this.time4 = t4;
        this.penalties = thePenalties;
    }
    public double pEarned() {
        return this.time1 + this.time2 + this.time3 + this.time4;
    }

    public double gPenalties() {
        return this.penalties * 5; 
    }
}

Currently, I'm trying to get my test cases to work but I keep getting the error "returnVal cannot be resolved to a variable"

class Examples {
    
    @Test
    void testEarned() {
        Result P1 = new Result(1, 30, 50, 56, 20, 2);
        returnVal = P1.pEarned();
        assertTrue(returnVal = 156);
    }
    @Test
    void testPenalties() {
        Result P1 = new Result(1, 30, 50, 56, 20, 2);
        returnVal = P1.gPenalties();
        assertTrue(returnVal = 10);
    }
}

I'm new to Java and for this assignment, I'm not supposed to have any inputs for the pEarned and gPenalties methods