The Willow Run Outlet Mall has two Haggar Outlet Stores, one located on Peach Street and the other on Plum Street. The two stores are laid out differently, but both store managers claim their layout maximizes the amounts customers will purchase on impulse. A sample of ten customers at the Peach Street store revealed they spent the following amounts more than planned: $17.58, $19.73, $12.61, $17.79, $16.22, $15.82, $15.40, $15.86, $11.82, $15.85. A sample of fourteen customers at the Plum Street store revealed they spent the following amounts more than they planned when they entered the store: $18.19, $20.22, $17.38, $17.96, $23.92, $15.87, $16.47, $15.96, $16.79, $16.74, $21.40, $20.57, $19.79, $14.83. For Data Analysis, a t-Test: Two-Sample Assuming Unequal Variances was used.
At the .01 significance level is there a difference in the mean amount purchased on an impulse at the two stores? Explain these results to a person who knows about the t test for a single sample but is unfamiliar with the t test for independent means.
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Hypothesis Test: Independent Groups (t-test, unequal variance)
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Peach Street
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Plum Street
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15.868
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18.2921
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mean
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2.3306
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2.5527
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std. dev.
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10
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14
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n
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20
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df
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-2.42414
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difference (Peach Street - Plum Street)
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1.00431
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standard error of difference
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0
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hypothesized difference
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-2.41
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t
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0.0255
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p-value (two-tailed)
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-5.28173
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confidence interval 99.% lower
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0.43345
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confidence interval 99.% upper
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2.85759
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margin of error
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