Peppered moths come in two colors, black and white. In a particular population,

Question

Peppered moths come in two colors, black and white. In a particular population, 60% are black, 40% are white, 50% are male, and 20% are black males. For each question, rewrite using proper probability notation, and calculate the probability. 2) a) Rewrite the percents using probability notation. b) Ifa moth is black, what is the probability that it is male? What is the probability that a moth is not a white female (in other words, that it is either black or male)? c) d) Are sex and color independent? Explain.

Explanation / Answer

A) P(black) = 0.6

P(White) = 0.4

P(male) = 0.5

P(female) = 0.5

P(black male) =0.2

P(white male) = 0.8

B) P(male | moth is black) = P(male and moth is black)/P(moth is black) = 0.2/0.6 = 0.33

C) P(not a white female) = P(black or male)

= P(black) + P(male) - P(black and male)

= 0.6 + 0.5 - 0.2

= 0.9

D) P(male and black) = 0.2

P(male) * P(black) = 0.5 * 0.6 = 0.3

As P(black and male) is not equal to P(black) * P(male) , so sex and colour are not independent.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.