What to fix in this code to calculate harmonic mean with for loop?

I'm working on a homework assignment to calculate the harmonic mean with a for-loop. I recognize there is a MATLAB function to do this already.

I don't really understand how to use for loops to do a summation. The equation I need to create a loop for is: n/[(1/x1)+(1/x2)+...+(1/xN)] where n is the number of data entries, x.

This is what I have currently, which I tried to adapt unsuccessfully from a code for geometric mean:

 data=[92.3 93.2 91.9 93.5 92.7 93.1 93.8 92.4];
n=length(data); % n is the number of entries of x in the harmonic mean.
harmonic_mean=0
for q=1:n
    z=data(q)
    x=harmonic_mean+(1/z)
    harmonic_mean=x
end

This is not returning the same answer as the equation I've been provided. Could someone help me understand why my code isn't doing a repetitive summation and how to alter it to get that?

Answer 1

[Geoff Hayes]

Trent - you can consolidate the last two lines of code (of your for loop) to

 harmonic_mean = harmonic_mean + 1/z;

which should provide the same answer as your code. However, note that the above isn't the harmonic mean but rather is the denominator for the Harmonic Mean equation so should be renamed to something else, say sumOfInverses

sumOfInverses = 0;
for q=1:n
    sumOfInverses = sumOfInverses + (1/data(q));
end

with the Harmonic Mean being

 harmonicMean = n/sumOfInverses;

as per your equation.