Question

A company is testing a new medicine for migraine medication using 250 participants.  Each participant was directed to take the medicine (either the new medication or a placebo) when the first symptom occurred and then to record whether the headache went away within 45 minutes or it persisted. The results are recorded below.

	Headache went away	Headache persisted	TOTAL
New medicine	132	18	150
Placebo	56	44	100
total	188	62	250

a. If one participant is selected at random, what is the probability that he/she took the new medicine and the headache went away? Leave answers as fractions.

b.  If one participant is selected at random, what is the probability that he/she took the new medicine or the headache went away?

c. If two different participants are selected, what is the probability that both of them took the new medicine? what is number c)

Answer 1

Sol Given table, Headache went away Headache persisted Total New Medicine 132 18 150 Placebo 44 100 Tod 62 250 P(New medcine AND headache went away) = Number of participants who took New medicine and Headache went away Total Number of participants 132 b) P(took the new medicine or The head ache went away) = P took the new medcine) + (head ache went away) - new medcine and head ache went away) Pl took the 2 SU c) are selected, the The new medcine = 250 Role of two different participants probability that both of them look 150! 2: 1481 1175 250! 31125 150c2 149 250 ca 415 2! 248!