How to write the Skewness program for the TI-89?

Click APPS, and find the Program Editor. CLICK ENTER.

Scroll down to New. CLICK ENTER

Type the Name of the program SKEW(a). CLICK ENTER

You should see:

Skew(a)

Prgm

Go to Catalog  and find the function dim. CLICK ENTER

Type letter a, close parenthesis and click STO->.

You should see:

Dim(a)->n

Repeat the same for functions mean, and stdDev.

You should see:

Mean(a)->m

stdDev(a)->s

Type:

0->t CLICK ENTER

Find the function For in the CATALOG. CLICK ENTER

Then type i,1,n

You should see:

For i,1,n

Then carefully type the following instruction. Make sure the instruction EndFor is after this expression.

n/((n-1)*(n-2))*(a[i]-m)^3/s^3+t->t

EndFor

 Disp “skew=”, t

EndPrgm

To check the program, create a list with the values:

1,2,2,3,3,3,4,4,4,4,5

when you run the program, select that list and click enter. You should get the value:

SKEW= -0.422465427

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