Hi, I wanted to get a quick look over for my program see if there were any flaws.. I think it's complete. specifications and program in link thanks..

I think the only thing i'm missing is the mean of the means (not very difficult but I am feeling lazy after working on this all day)

and the histogram displaying correctly at the moment I'm not sure it would display with the randomly generated values I think it should be simple to input I'm just new to MATLAB.. Thank you :)

Specifications for program below:

1. Generate 100 samples of size 225 random numbers from U(-3,6). For each of these 100 samples calculate the mean.

a) Find the simulated probability that the mean is between 1 and 2.

b) Find the mean of the means.

c) Find the standard deviation of the means.

d) Draw the histogram of the means.

nsamples=100;

samplenum = 1:nsamples;

  %setting number of samples and the sample amt. i.e. here there 
  %is only 1 sample of number 100

n = 225;
  
  %sample size 225

a = 1;

  %setting first mean value of 1

b = 2;

  %setting second mean value of 2

theProbability = sum(nsamples > a & nsamples < b) / n;

  %finding the probability that the mean is between a and b

a + (b-a)*rand()

  %gives uniform random values in the interval [a,b]

data = a + (b-a)*rand(1, nsamples);

  %setting data values

cMean = mean(data)

  %calculating mean of data

cStdDev = std(data)

  %calculating standard deviation of data

z = normrnd(-3,6,n,1);

  %setting distribution of random numbers U(-3,6) (n)=(U) here

hist(z,-9.75:.5:9.75);

  %setting histogram values for x-axis (labeled here as z)

xlim([-10 10]);

  %setting x-axis coordinates

title('Generating 100 Samples of Size 225 Simulated U(-3,6) Random Numbers Histogram Question 1 Part d)');
  
  %title of histogram
  
xlabel('Z');

  %labeling x-axis

ylabel('Frequency');

  %labeling y-axis

Answer 1

[Alexandra Harkai]

The random sample comes from a normal instead of a uniform sample (assuming U stands for uniform). Also all the data you generated is in the (a,b) interval which will give you 1 for question a).

nsamples=100;  % number of samples
n = 225;  % sample size 225
a = 1;
b = 2;
data = -3+9*rand(nsamples, n);  % random 100x225 data sample from a uniform (0,1) distribution
cMean = mean(data, 2);  % mean of each sample

answer_a = sum(cMean > a & cMean < b)/nsamples;  % how many data means are between a and b
answer_b = mean(cMean);
answer_c = std(cMean, 1);

hist(cMean);
title('Generating 100 Samples of Size 225 Simulated U(-3,6) Random Numbers Histogram Question 1 Part d)');  %title of histogram  
xlabel('Z');  %labeling x-axis
ylabel('Frequency');  %labeling y-axis

[HrMmz]

Thank you so much!

[Alexandra Harkai]

Np. Hope it explains itself and helps to see where the first version did something funky.

[HrMmz]

Hi! Thanks I totally know what you mean, having what you know vs. what you need to know!

Also if you're interested here is a second very similar program basically the same exact concept again if you're interested..

bonus answer points time hehe

..and the raw link in case :)

http://www.mathworks.com/matlabcentral/answers/314840-a-few-key-concepts-to-take-from-one-complete-program-and-apply-to-another-very-similar-second-comput

thanks again for the help here from yesterday happy holidays