# Finding Probability using tree tables and outcome tables.

• Oct 13th 2008, 02:15 PM
Skoz
Finding Probability using tree tables and outcome tables.
A tes has four true/false questions.

A) draw a tree diagram showing all possible true/false combinations for the answers to the test.

1)T =T/F
F =T/F
2)T =T/F
F =T/F
3)T =T/F
F =T/F
4)T =T/F
F = T/F

16 different combos.

b) Determine the probability that student will get four correct
1/2 chance of getting each correct so 1/2 x 1/2 x 1/2 x1/2 (4 questions, 4x)= 1/16

c) Determine the probability that student will get three questions correct by guessing.
This one i kept getting 1/8 i might be solving it the wrong way but I followed the same pattern as part b.
• Oct 13th 2008, 06:14 PM
mr fantastic
Quote:

Originally Posted by Skoz
A tes has four true/false questions.

A) draw a tree diagram showing all possible true/false combinations for the answers to the test.

1)T =T/F
F =T/F
2)T =T/F
F =T/F
3)T =T/F
F =T/F
4)T =T/F
F = T/F

16 different combos.

b) Determine the probability that student will get four correct
1/2 chance of getting each correct so 1/2 x 1/2 x 1/2 x1/2 (4 questions, 4x)= 1/16

c) Determine the probability that student will get three questions correct by guessing.
This one i kept getting 1/8 i might be solving it the wrong way but I followed the same pattern as part b.

(c) There are 4 branches on your tree diagram corresponding to three correct guesses and one wrong guess. Each branch has a probability of 1/16. So it's 4 (1/2)^4 = 1/4.