Question

In a survey, 80% of people own a smart phone, 40% of people own a tablet computer, and 25% of people own both. what is the probability that a person owns a tablet computer given that he or she owns a smart phone?

Answer 1

To get the probability of a single random event, this formula must be followed 

Probability = event/s  /  number of outcomes 

In this problem, the number of outcomes is 80%  40% and 25%. The event is that a person owns a tablet computer that owns also a smartphone. 

.8 +.4+.25  = 1.45 x 100 = 145% 

Probability = .25 / 1.45= 0.1724 x 100 = 17.24%

Therefore, the probability that a person owns a tablet computer and smartphone is 17.24%. 

Answer 2

25 % of people own a smart phone and a tablet computer. So,the probability that a person owns a tablet computer given that he or she owns a smart phone is the probability that this person has a tablet computer and a smart phone. 25% is 1/4 probability.