Answer:
A) attached
B) 15/36 = 5/12
C) 21/36 = 7/12
D) 18/36 = 1/2
E) 32/36 = 8/9
Explanation:
A probability distribution is a table showing all the possible values a discrete random variable can take, plus the probability that it'll take each value.
Let X be the score of a pair of fair six-sided dice
X can take the values 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12
Create a sample space (attached) to visually see the sums of different combinations and to help construct the probability distribution table (attached)
B) Reading from the table:
P(X ≥ 8) = P(X=8) + P(X=9) + P(X=10) + P(X=11) + P(X=12)
= 5/36 + 4/36 + 3/36 + 2/36 + 1/36
= 15/36 = 5/12
C) Reading from the table:
P(X ≤ 7) = P(X=7) + P(X=6) + P(X=5) + P(X=4) + P(X=3) + P(X=2)
= 6/36 + 5/36 + 4/36 + 3/36 + 2/36 + 1/36
= 21/36 = 7/12
D) Reading from the table:
P(X is even) = P(X=2) + P(X=4) + P(X=6) + P(X=8) + P(X=10) + P(X=12)
= 1/36 + 3/36 + 5/36 + 5/36 + 3/36 + 1/36
= 18/36 = 1/2
E) Reading from the table:
P(3≤X≤10) = P(X=3) + P(X=4) + P(X=5) + P(X=6) + P(X=7) + P(X=8) +
P(X=9) + P(X=10)
= 2/36 + 3/36 + 4/36 + 5/36 +6/36 + 5/36 + 4/36 + 3/36
= 32/36 = 8/9