show probabilities (-inf+inf, -3dev-3dev and so on....)

show probabilities (-inf+inf, -3dev-3dev and so on....)

>> mu = 12.5;

sigma = 3.75;

xs = [0:.01:25];

ys = normpdf(xs, mu, sigma);

clf;

plot(xs, ys);

Follow with the mean and std

[John D'Errico]

Um, what is your question?

[Amer Al-Maashani]

show probabilities (-inf+inf, -3dev-3dev and so on....)

Follow with the mean and std

[John D'Errico]

show what probabilities? Mean and std of what? What is your question?

[Amer Al-Maashani]

showing (-inf+inf, -3dev-3dev) probabilities in Matlab. mean = 12.5 , std=3.75

[James Tursa]

Can you copy & paste the actual wording of the assignment?

[Amer Al-Maashani]

it is not an assignment. I have this example which plotting the pdf function.

matlab code:

>> mu = 12.5; % mean

sigma = 3.75; % standard deviation

fh=@(x) exp(-((x-mu).^2)./(2*(sigma^2)))*(1/sqrt(2*pi*(sigma^2))); % PDF function

X = 0:.01:25;

p = plot(X,fh(X),'b-')

and my teacher is asking me this question.

show probabilities (-inf+inf, -3dev-3dev and so on....)

Follow with the mean and std

[John D'Errico]

I think it is your teacher you need to talk to, to explain what you are asked to do.

[James Tursa]

"show probabilities (-inf+inf, -3dev-3dev and so on....)"

I have no idea what is being asked for here. Cumulative probability between the two values? Or ...?

[Amer Al-Maashani]

'by integrating pdf You can find the probability of the signal apperance in given level ranges' teacher's explanation.

Answer 1

[James Tursa]

"Integrating pdf" and "probability ... in given level ranges" sounds like the teacher wants you to use the cdf to get the cumulative probability between a range of values. E.g., maybe this is what is being asked:

>> mu = 12.5;
>> sigma = 3.75;
>> pd = makedist('Normal','mu',mu,'sigma',sigma); % Make a Normal pdf
>> cdf(pd,inf) - cdf(pd,-inf) % the integrated probablility between -inf and +inf
ans =
     1
>> cdf(pd,mu+3*sigma) - cdf(pd,mu-3*sigma) % the integrated probablity between mu-3sigma and mu+3sigma
ans =
    0.9973