Application Guide

338 Lists&Spreadsheet Application
• H
a
: m>m
0
This test is used for large populations that are normally distributed. The standard
deviation must be known.
This test is useful in determining if the difference between a sample mean and a
population mean is statistically significant when you know the true deviation for a
population.
ttest (tTest)
Performs a hypothesis test for a single unknown population mean, m, when the
population standard deviation, s, is unknown. 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 similar to a z-test, but is used when the population is small and normally
distributed. This test is used more frequently than the z-test because small sample
populations are more frequently encountered in statistics than are large populations.
This test is useful in determining if two normally distributed populations have equal
means, or when you need to determine if a sample mean differs from a population
mean significantly and the population standard deviation is unknown.
2-Sample z Test (zTest_2Samp)
Tests the equality of the means of two populations (m
1
and m
2
) based on independent
samples when both population standard deviations (s
1
and s
2
) are known. The null
hypothesis H
0
:m
1
=m
2
is tested against one of the alternatives below.
• H
a
: m
1
ƒm
2
• H
a
: m
1
<m
2
• H
a
: m
1
>m
2
2-Sample t Test (tTest_2Samp)
Tests the equality of the means of two populations (m
1
and m
2
) based on independent
samples when neither population standard deviation (s
1
or s
2
) is known. The null
hypothesis H
0
:m
1
=m
2
is tested against one of the alternatives below.
• H
a
: m
1
ƒm
2
• H
a
: m
1
<m
2
• H
a
: m
1
>m
2
1-Prop z Test (zTest_1Prop)
Computes a test for an unknown proportion of successes (prop). It takes as input the
count of successes in the sample x and the count of observations in the sample n.