The tree diagram of the problem above is attached
There are four outcomes of the two events,
First test - Cancer, Second Test - Cancer, the probability is 0.0396
First test - Cancer, Second Test - No Cancer, the probability is 0.0004
First test - No Cancer, Second Test - There is cancer, the probability is 0.0096
First test - No cancer, Second Test - No cancer, the probability is 0.9054
The probability of someone picked at random has cancer given that test result indicates cancer is

The probability of someone picked at random has cancer given that test result indicates no cancer is
Answer: Y=-5x+30
Step-by-step explanation:
First, you have to find the slope of graph so you find the rise over run Y/X. Since the X values are being measured by 1’s, and the Y values are being measure by 5’s, your slope would be -5 (not 5 as the graph line is decreasing therefore it is negative). To find b, you find the Y intercept of the graph (where Y is when X=0) and in this case, the y intercept is 30. So the equation that describes what is occurring in the graph is Y=-5x+30 as a linear equation is written as Y=mx+b. You can check If the equation is correct by substituting the x and y values of a specific coordinate point on the graph. For example: 25= -5(1)+30. This gives you 25=25 so the equation is correct.
The mean score is 3.08.
There is 1 quiz with score 1, so 1 point; 3 quizzes with score 2 for 3*2 = 6 points; 4 quizzes with score 3 for 4*3 = 12 points; 4 quizzes with score 4 for 4*4 = 16 points; and 1 quiz with score 5 for 5 points.
This is a total of 1+6+12+16+5 = 40 points.
This is out of 1+3+4+4+1 = 13 quizzes.
40/13 = 3.08