Question 250156
Pharmacology In placebo-controlled trials of ProzacŪ, a
drug that is prescribed to fight depression, 23% of the
patients who were taking the drug experienced nausea,whereas 10% of the patients who were taking the placebo experienced nausea.* 
a. If 50 patients who are taking ProzacŪ are selected, what
is the probability that 10 or more will experience nausea?
--
It's binomial with n=50 , p = 0.23 , 10 <= x <= 50
Prob = 1 - binomcdf(50, 0.23, 9) = 0.7436
------------------------------------------------------------------ 
b. Of the 50 patients in part a, what is the expected number
of patients who will experience nausea?
np = 50*0.23
--------------------- 
c. If a second group of 50 patients receives a placebo,
what is the probability that 10 or fewer will experience
nausea?
binomcdf(50,0.10,10)= 0.9906
---------------------
 
d. If a patient from a study of 1000 people, who are equally
divided into two groups (those taking a placebo and
those taking ProzacŪ), is experiencing nausea, what is
the probability that he/she is taking ProzacŪ? 
P(Prozac|nausea) = P(Prozac and nausea)/P(nausea)
= (0.23)/[(P(nausea|Prozac) + P(nausea|placebo)] = 0.23/(0.23 + 0.10)
= 0.23/0.33 = 0.6970
---------------
e. Since .23 is more than twice as large as .10, do you think
that people who take ProzacŪ are more likely to experience
nausea than those who take a placebo? Explain.
I'll leave that to you.
==================================
Cheers,
stan H.
0 solutions