% Filename: SleepingPillEfficacy.m
% M-file to estimate probability of sleeping better given that you take
% a sleeping pill.
% Set how many times to run the experiment
N = 1000;
% Set variables to sum up the probabilities of events
A = 0; % probability took sleeping pill
B = 0; % probability took sleeping pill + had improved sleep
% Run set of N experiments N times
for i = 1:N
% Set counters
a = 0; % took sleeping pill counter
b = 0; % took sleeping pill + had improved sleep counter
% Run experiment N timess
for j = 1:N
% Select one participant
x = DrugTesting;
% If participant took sleeping pill
if x(1,1)==1
a = a + 1;
% If participant also had improved sleep
if x(1,2)==1
b = b + 1;
end
end
end
% Add the probabilities for this set of N experiments
% to the running sum
A = A + a/N;
B = B + b/N;
end
% Print out result
fprintf('P(improved sleep|took sleeping pill)=%6.4f\n',(B/N)/(A/N));