Help 14,15 ​

14....Mutually exclusive.....means that two things cannot happen simultaneously....so....you can't roll a 3 and a 4  at the same time...

P(placebo and improvement)  =  \(\frac{\text{number who received placebo and reported improvement}}{\text{total number who participated in the study}}\)

Let the total number of people who participated in the study  =  t

80% of those who participated in the study received med A .  So…
20% of those who participated in the study received a placebo.

number of those who received the placebo   =   0.2t

62% of those who received the placebo reported no improvement.  So…
38% of those who received the placebo reported improvement.

number who received placebo and reported improvement  =  0.38( 0.2t )

P(placebo and improvement)  =  \(\frac{0.38(0.2t)}{t}\)   =   0.38(0.2)   =   0.076   =   7.6%