Question

What is the probability that a student selected at random is a boy?

Answer 1

Answer:

Pr(B) = 0.69

Pr(J/B) = 0.35

Pr(J∩B) = 0.14

Pr(G/J') = 0.66

Pr(G) = 0.31

Step-by-step explanation:

Applying,

Pr = possible outcome (a)/Total outcome(t)

(1) Pr(B) = a/t............ Equation 1

From the diagram

Given: a = 220+65+35 = 320, t = 220+65+35+145 = 465

Substitute these values into equation 1

Pr(B) = 320/465

Pr(B) = 0.69

(2) Pr(J/B) = (35+65)/(220+65)

Pr(J/B) = 100/285

Pr(J/B) = 0.35

(3) Pr(J∩B) = 65/465

Pr(J∩B) = 0.14

(4) Pr(G/J') = 145/220

Pr(G/J') = 0.66

(5) Pr(G) = 145/465

Pr(G) = 0.31