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Unformatted text preview: ue<α H0: μ1 – μ2= D0
Ha: μ1 – μ2≠ D0
reject H0 if tSTAT < –tα/2 or tSTAT >
tα/2 or if pvalue<α Example What are the hypotheses for testing
whether the mean mpg of M cars is
greater than the mean mpg of J
cars? Specific Motors of Detroit has
developed a new automobile
known as the M car. 24 M cars
and 28 J cars (from Japan)
Is μM>μJ?
were road tested to compare
mpg performance. The sample
Hypotheses:
statistics are: H0: μM–μJ ≤ 0
M μM
Cars
Ha: Cars–μJJ > 0 Hypothesis Tests n
x
s 24 28 29.8 27.3 2.56 test
statistic
upper tail
test
lower tail
test 1.81
twotailed
test Difference Between 2
Population Means
(x1 − x2)− D0
tSTAT =
s 2 s22, df
1
+ =…
n1 n2
H0: μ1 – μ2 ≤ D0
Ha: μ1 – μ2 > D0
reject H0 if tSTAT > tα or pvalue<α H0: μ1 – μ2 ≥ D0
Ha: μ1 – μ2 < D0
reject H0 if tSTAT <– tα or pvalue<α H0: μ1 – μ2= D0
Ha: μ1 – μ2≠ D0
reject H0 if tSTAT < –tα/2 or tSTAT >
tα/2 or if pvalue<α Example How can we conclude at 0.05 level of
significance that the mean mpg of M
cars is greater than the mean mpg of J
cars? Specific Motors of Detroit has
developed a new automobile
known as the M car. 24 M cars
and 28 J cars (from Japan)
were road tested to compare
mpg performance. The sample
statistics are: Hypothesis Tests M Cars
n
x
s J Cars 24 28 29.8 27.3 2.56 test
statistic
upper tail
test
lower tail
test 1.81
twotailed
test Difference Between 2
Population Means
(x1 − x2)− D0
tSTAT =
s 2 s22 , df =
1
+
n1 n2
H0: DM–J ≤ 0
Ha: DM–J > 0
reject H0 if tSTAT > tα or pvalue<α H0: μ1 – μ2 ≥ D0
Ha: μ1 – μ2 < D0
reject H0 if tSTAT <– tα or pvalue<α H0: μ1 – μ2= D0
Ha: μ1 – μ2≠ D0
reject H0 if tSTAT < –tα/2 or tSTAT >
tα/2 or if pvalue<α Example How can we conclude at 0.05 level of
significance that the mean mpg of M
cars is greater than the mean mpg of J
cars? Specific Motors of Detroit has
developed a new automobile
known as the M car. 24 M cars
and 28 J cars (from Japan)
were road tested to compare
Usingα=0.05, reject H0
mpg performance. The sample
tSTAT >
statistics are: z.05 (critical value
approach) tail
; or pvalue < 0.05 (p uppertest M Cars J Cars 24 28 29.8 27.3 value approach) Hypothesis Tests n
x
s if: test
statistic 2.56 lower tail
test 1.81
twotailed
test Difference Between 2
Population Means
(x1 − x2)− D0
tSTAT =
s 2 s22 , df =
1
+
n1 n2
H0: DM–J ≤ 0
Ha: DM–J > 0
reject H0 if tSTAT > tα or pvalue<α H0: μ1 – μ2 ≥ D0
Ha: μ1 – μ2 < D0
reject H0 if tSTAT <– tα or pvalue<α H0: μ1 – μ2= D0
Ha: μ1 – μ2≠ D0
reject H0 if tSTAT < –tα/2 or tSTAT >
tα/2 or if pvalue<α Example What is the value of the tSTAT (test
statistic)? Specific Motors of Detroit has
developed a new automobile
known as the M car. 24 M cars
and 28 J cars (from Japan)
were road tested to compare
mpg performance. The sample
statistics are:
M Cars J Cars Hypothesis Tests n
x 24 27.3 s...
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This document was uploaded on 03/05/2014.
 Spring '13

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