%  Creates a figure showing a binomial pdf overlapping the normal
%  approximation to a binomial.
%
%  Figure caption:  The normal approximation to the binomial.
%  Black circles are pdf values for a B(100, 0.4) distribution;
%  the solid line is the pdf of a normal having the same mean and variance.

xvals = 10:70;

%  Set binomial parameters.  
n = 100;
p = 0.4;

binomialMean = p * n;
binomialVariance = n * p * (1 - p);

% Compute and plot PDFs.
binomialPdfValues = binopdf(xvals, n, p);
normalPdfValues = normpdf(xvals, binomialMean, sqrt(binomialVariance));

plot(xvals, normalPdfValues, '-k', 'LineWidth', 2)

hold on;
plot(xvals, binomialPdfValues, 'ok', 'MarkerSize', 5, 'LineWidth', 2)

%  Set style parameters.
set(gca, 'Box', 'off', 'FontSize', 22, ...
         'XTick', 10:10:70, 'YTick', [], 'TickDir', 'out')

set(gcf, 'Position', [200, 100, 700, 500])