Question

in a group of 140 adults, 92 watch tennis, 81 play a sport and 40 do neither. find the probability that an adult chosen at random from those who watch tennis does not play a sport

Answer 1

38 of them that watch tennis would not play a sport.

Answer 2

Explanation:

27.7%

Step-by-step explanation:

Let's call:

n: the number of adults interviewed

t: number of adults who watch tennis

d: number of adults who practice some sport

x: number of adults who watch tennis and do not practice a sport

The probability that a randomly chosen adult watches tennis and does not play any sports is calculated as follows:

- We calculate the probability that a selected adult will see tennis.

P(t) = 92/140 = 0.657

- We calculate the probability that an adult plays a sport:

P(d) = 81/140 = 0.5786

- We calculate the probability that an adult will see tennis and play some sport (See diagram attached)

P (t ∩ d) = 0.657 (0.5786) = 0.3802

Finally the probability that an adult who sees tennis does not play any sport is:

P(x) = P(t) - P(t ∩ d) = 0.657 - 0.3802

P(x) = 0.277