A pharmaceutical company is testing the effectiveness of a new drug for asthma patients. The drug is given to 100 volunteers who suffer from asthma, while a placebo is given to 100 other volunteers who also suffer from asthma. After 4 weeks, the volunteers are asked if they noticed improvement in their asthma symptoms. The results of the survey are shown in the contingency table below. What is the probability that a volunteer received the placebo given that he did not report a noticeable improvement in symptoms?

Question

hap1236 · Answer

@jhonyy9

hap1236 · Answer

A. .2667 	
  B. .733 	
  C. .32 	
  D. .88

hap1236 · Answer

Received the Drug	68	32	100
Received the Placebo	12	88	100
Totals	80	120	200

evoker · Answer

What are you column headings

hap1236 · Answer

improved, did not approve, totals

evoker · Answer

Ok so look at group that did not approve, and see how many had placebo

hap1236 · Answer

88

evoker · Answer

Sure and the larger group are people that did not approve which is 120

hap1236 · Answer

ok??

evoker · Answer

So 88/120

evoker · Answer

For these conditional probabilities you narrow the problem down to just the row or column that describes the given.

hap1236 · Answer

.733