Question

Homework Set 5: Problem 9 Previous Problem List Next (1 point) Listed below is a table detailing a few demographics of the passengers who survived or died on the Titanic. Survived Died Total Men 332 1360 1692 Women 318 104 422 Boys Girls Total 2 9 27 706 35 1 8 1517 644 5 2223 (a) If a name is randomly selected from the passenger manifest of the Titanic find the probability of selecting a survivor or a girl? (b) If a name is randomly selected from the passenger manifest of the Titanic find the probability of selecting someone who died or a gini? Note: You can earn partial credit on this problem. Preview My Answers Submit Answers You have attempted this problem 2 times. Your overall recorded score is 0%. You have unlimited attempts remaining.

i know there are many quesitons with answers that looks like this one, but i have tried to follow other"s explanations and it does not work

Answer 1

We use the following formula to calculate both the parts

Given 2 events A, B

The probability of A or B is

P(AUB) = P(A) + P(B) - P(ANB)

a) First we calculate

If a name is randomly selected from the passenger manifest of the Titanic, the probability of selecting a survivor is

Total number of survivors Total number of passengers 706 2223 = 0.3176

If a name is randomly selected from the passenger manifest of the Titanic, the probability of selecting a girl is

P(girl) = Total number Total number of Girls Total number of passengers = 45 2223 = 0.0202

If a name is randomly selected from the passenger manifest of the Titanic, the probability of selecting a survivor and a girl is

P(survivor girl) = - number of survived who are Girls Total number of passengers 27 2223

Now we can get the needed probability

If a name is randomly selected from the passenger manifest of the Titanic, the probability of selecting a survivor or a girl is

girl) P(survivor U girl) = P(survivor) + P(girl) - P(survivor = 0.3176 + 0.0202 -0.0121 = 0,3257

ans: 0.3257

b) We calculate the following

If a name is randomly selected from the passenger manifest of the Titanic, the probability of selecting someone who died is

Total number who died Total number of passengers 1517 2223 = 0.6824 ?

If a name is randomly selected from the passenger manifest of the Titanic, the probability of selecting a girl is

P(girl) = Total number Total number of Girls Total number of passengers = 45 2223 = 0.0202

If a name is randomly selected from the passenger manifest of the Titanic, the probability of selecting someone who died and a girl is

P(died n girl) = number died who are Girls Total number of passengers 18 2223 = 0.0081

finally,

If a name is randomly selected from the passenger manifest of the Titanic, the probability of selecting someone who died or a girl is

P(died U girl) = P(died) + P(girl) - P(died n girl) = 0.6824 +0.0202 -0.0081 = 0.6946

ans: 0.6946