Microsoft Office Tutorials and References

In Depth Information

**Deviating from the Middle**

Figure 9-9:

Standardizing a

distribution

of data.

The STANDARDIZE function takes three arguments:

✓
Data point

✓
Mean of the distribution

✓
Standard deviation of the distribution

For example, this is the formula in cell E7: =STANDARDIZE(B7,C$2,C$3).

Note how a few key properties of the distribution have changed after the

values are standardized:

✓
The standard deviation is 1.

✓
The mean is 0.

✓
The standardized values fall within the range –1.77 to 1.72.

This third point is determined by using the MIN and MAX functions,

respectively, in cells I7 and I8. Having values fall in the range –1.7 to 1.7 allows the

values to be analyzed with the Areas Under the Standard Normal Curve table

mentioned earlier. That is, it’s a property of standard normal curves to have

all values fit into this range.

Here’s how to use the STANDARDIZE function:

1. Enter a list of numerical values into a column.

It makes sense if this list is a set of random observable data, such as

heights, weights, or amounts of monthly rainfall.