Hypothesis testing for difference between two population means.
1. A researcher randomly sampled 30 graduates of an MBA program and recorded data concerning their starting salaries. Of primary interest to researcher was the effect of gender on starting salaries. Analysis of the mean salaries of the females and males in the sample is given below.
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Hypothesized Difference
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0
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Level of Significance
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0.05
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Population 1 Sample
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|
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Sample Size
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18
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Sample Mean
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48266.7
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Sample Standard Deviation
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13577.63
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Population 2 Sample
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|
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Sample Size
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12
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Sample Mean
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55000
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Sample Standard Deviation
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11741.29
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Difference in Sample Means
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-6733.3
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t-Test Statistic
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-1.40193
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Lower-Tail Test
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|
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Lower Critical Value
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-1.70113
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p-Value
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0.085962
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The researcher was attempting to show statistically that the female MBA graduates have a significantly lower mean starting salary than male MBA graduates. According to the test run, which of the following is an suitable alternative hypothesis?
b. The researcher was attempting to show statistically that the female MBA graduates have a significantly lower mean starting salary than the male MBA graduates. From the analysis in Table 10-2, the right test statistic is:
1. 0.0860
2.- 1.4019
3.- 1.7011
4.- 6,733.33
2. A real estate company is interested in testing whether, on average, families in Gotham have been living in their current homes for less time than families in Metropolis have. Assume that the two population variances are equal. A random sample of 100 families from Gotham and a random sample of 150 families in Metropolis yield the following data on length of residence in current homes.