Question

Your statistics professor comes to class with a big urn that she claims contains 9999 blue marbles and 1 red marble. You draw out one marble at random and finds that it is red. Would you be willing to tell your professor that you think she is wrong about the distribution of colours? Why or why not? What are you assuming in making your decision? What if instead, she claims there are nine blue marbles and 1 red one (and you draw out a red marble)?

Answer 1

(1)

Blue marbles = 9999

Red marble =1

Total = 10,000

So,

P(1 Red) = 1/10,000 = 0.0001

Since P(1 Red) = 0.0001 is less than 0.05, it is unusual event. So, I would be willing to tell my Professor that I think she is wrong about the distribution.of colors.

(2)

Blue marbles = 9

Red marble =1

Total = 10

So,

P(1 Red) = 1/10= 0.10

Since P(1 Red) = 0.10 is greater than 0.05, it is not unusual event. So, I would not be willing to tell my Professor that I think she is wrong about the distribution.of colors.