Microsoft Office Tutorials and References

In Depth Information

**ZTEST**

The equation for the cumulative distribution function is

The equation for the probability density function is

Figure 11.55

Use either TRUE or

FALSE for the

cumulative argument with the

WEIBULL
function.

ZTEST

ZTEST
returns the two-tailed P-value of a z-test.

=ZTEST(array,x,sigma)

The
ZTEST
function is used to generate a standard score for
x
for the data set, and returns the

two-tailed probability for the normal distribution. Use this function to assess whether a

particular data value is from a particular population. Figure 11.56 shows an example of
ZTEST
.

Is the data set against which to test
x.

ARRAY

Is the value to test.

X

Is the population standard deviation. If omitted the sample standard

deviation is used.

SIGMA

The equation for
ZTEST
is