MATLAB: Average of terms

average

Hello, I want to know that if i have row matrix of 1×160 and i want to take average upto certain values of the matrix then how can i do that?

mean(x(1:num)); %where num is the number you want to mean to.

EDITED

[num,~,~]=xlsread('myexcelfile.xlsx')
RESULT = num(:,1).*num(:,3)
average = mean(RESULT)

By default, it will give the sample standard deviation. Call it as

std(x,1)

to get the population. That is explained in the documentation for std, in the section describing the input argument weight.