Using Lists & Spreadsheet 583
2-Prop z Interval (zInterval_2Prop) computes a confidence
interval for the difference between the proportion of successes in two
populations (p
1
-p
2
). It takes as input the count of successes in each
sample (x
1
and x
2
) and the count of observations in each sample
(n
1
and n
2
). The computed confidence interval depends on the user-
specified confidence level.
This test is useful in determining if two rates of success differ because of
something other than sampling error and standard deviation. For
example, a bettor could use this test to determine if there is an
advantage in the long run by playing one game or machine versus
playing another game or machine.
Linear Reg t Intervals (LinRegtIntervals) computes a linear
regression t confidence interval for the slope coefficient b. If the
confidence interval contains 0, this is insufficient evidence to indicate
that the data exhibits a linear relationship.
Multiple Reg Intervals (MultRegIntervals) computes multiple
regression prediction confidence interval for the calculated y and a
confidence for y.
Stat Tests
Supported Statistical tests
Hypothesis tests are available from the Lists & Spreadsheets application.
For complete information regarding these functions, refer to the
TI-Nspire™ Reference Guide details for the function name provided in
parentheses.
Some of the wizards for Stat Tests display a
Draw check box. By default,
the box is not checked. Checking the box creates a Data & Statistics work
area on the page and plots the results in that work area.
z test (zTest) performs a hypothesis test for a single unknown
population mean, m, when the population standard deviation, s, is
known. It tests the null hypothesis H
0
: m=m
0
against one of the
alternatives below.
•H
a
: mƒm
0
•H
a
: m<m
0
•H
a
: m>m
0
This test is used for large populations that are normally distributed. The
standard deviation must be known.