One-way anova with unequal sample sizes

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Valentina Richard 2022-6-11

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https://ww2.mathworks.cn/matlabcentral/answers/1738580-one-way-anova-with-unequal-sample-sizes

编辑： dpb 2022-6-12

I am asked to compute a MATLAB function which runs a one-way anova test on the following samples

s1=2,6,6,5,2,7,6,4,5,4,1

s2=10,6,6,6,2,11,9,6,11

s3=1,2,5,10,0,3,4,3

and s4=9,5,7,6,8,6,8,8,10

and i am told that as inputs i have to insert these four samples and the level of significance which i have chosen to be 0.05.

The issue i am facing is that I cannot compute these samples into a single matrix as they are unequal and this is giving me a lot of trouble. I also am asked to use an 'if' loop when deciding whether null hypothesis should be accepted or rejected. Can someone please help me out? I would really appreciate

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dpb 2022-6-12

编辑：dpb 2022-6-12

在 MATLAB Online 中打开

From what starting point? Show us what you've got so far...and I don't know what a "function document" is???

I'm old school; never use any of the new-fangled display stuff if it has something to do with it; you'll have to find somebody much younger than I... :)

But, from the command line using the output from anova1 for the data you had,

x = 0:0.01:10;              % range for F variate
y = fpdf(x,3,33);           % compute pdf of F with 3,33 num/den DOF
plot(x,y)                   % plot the total pdf
ylim([0 0.025])             % expand the tail region vertically to see something
Fc=6.32;                    % the F statistic
ixc=(x>=Fc);                % indices from Fc
hA=area(x(ixc),y(ixc).',0); % fill the area to RHS

If you compute

> 1-fcdf(Fc,3,33)
ans =
    0.0017
>>

you see you get same result as in the anova table....

Now, how you're supposed to turn this in to your instructor in class I've no klew, but that's the basic steps.

Interestingly, the makedist function doesn't support the F-distribution directly to make the distribution object; I've no klew about why that might be so, either.

Valentina Richard 2022-6-12

IT WORKED !! Thank you so much for your help you have no idea how much i appreciate. Hope you have a great rest of the day :))

dpb 2022-6-12

编辑：dpb 2022-6-12

Glad to help...teaching is part of the attraction besides just the play...you had shown enough "go get 'em" on assignment with just guidance to make the last not seem like doing too much.

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