Assignment:
Q1: Past records suggest that the mean annual income μ1, of teachers in state of Arizona is greater than or equal to the mean annual income μ2, of teachers in Nevada. In a current study, a random sample of 10 teachers from Arizona and an independent random sample of 10 teachers from Nevada have been asked to report their mean annual income. The data obtained are as follows.
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Annual income in dollars
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Arizona
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44409, 45356, 31838, 29931, 38724, 38168, 31404, 20258
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Nevada
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35530, 40114, 47821, 47959, 45600, 39407, 42107, 42961, 45098, 45855
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Q2: The population standard deviation for mean annual income of teachers in Arizona and in Nevada are estimated as 6300 and 6500, respectively. It is also known that both populations are approximately normally distributed. At the 0.10 level of significance, is there sufficient evidence to reject the claim that the mean annual income of teachers in state of Arizona is greater than or equal to the mean annual income of teachers in Nevada? Perform a one-tailed test. Then fill in the table below.
Carry your intermediate computations to at least three decimal places.
What is the null hypothesis?
What is the alternative hypothesis?
The type of test statistic? Z t F Chi Square
What is the value of the test statistic?
What is the p-value?
Can we reject the claim that the mean annual income of teachers from Arizona is greater than or equal to the mean annual income of teachers from Nevada? YES or NO
Q3: Past records suggest that the mean annual income, μ1 of teachers in state of Texas is greater than or equal to the mean annual income, μ2 of teachers in Indiana. In a current study, a random sample of 25 teachers from Texas and an independent random sample of 25 teachers from Indiana have been asked to report their mean annual income.The data obtained are as follows.
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Annual income in dollars
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Texas
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22401, 30580, 37661, 33677, 41717, 25776, 37375, 39448, 31733, 32622, 25818, 34901, 38390, 47586, 33447, 35571, 39271, 38525, 36355, 31532, 46282, 40086, 29233, 35960, 43347
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Indiana
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44525, 37565, 44159, 38591, 47124, 39015, 49805, 42187, 43510, 41955, 31092, 42640, 33642, 48291, 42513, 45958, 41802, 35623, 35930, 30863, 52693, 41892, 28658, 43603, 35121
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The population standard deviation for mean annual income of teachers in Texas and in Indiana are estimated as 6200 and 6500, respectively. It is also known that both populations are approximately normally distributed. At the 0.01 level of significance, is there sufficient evidence to reject the claim that the mean annual income of teachers in state of Texas is greater than or equal to the mean annual income of teachers in Indiana? Perform a one-tailed test. Then fill in the table below.
Carry your intermediate computations to at least three decimal places
What is the null hypothesis?
What is the alternative hypothesis?
The type of test statistic? Z t F Chi Square
What is the value of the test statistic?
What is the critical value at the 0.01 level of significance?
Can we reject the claim that the mean annual income of teachers from Texas is greater than or equal to the mean annual income of teachers from Indiana? YES or NO
Q4: Medical researchers interested in determining the relative effectiveness of two different drug treatments on people with a chronic mental illness established two independent test groups. The first group consisted of 15 people with the illness, and the second group consisted of 9 people with the illness. The first group received treatment 1 and had a mean time until remission of 175 days, with a standard deviation of 9 days. The second group received treatment 2 and had a mean time until remission of 168 days, with a standard deviation of 7 days. Assume that the populations of times until remission for each of the two treatments are normally distributed with equal variance. Can we conclude, at the 0.1 level of significance, that the mean number of days before remission after treatment 1, μ1 is greater than the mean number of days before remission after treatment 2, μ2?
Perform a one-tailed test. Then fill in the table below.
Carry your intermediate computations to at least three decimal places
What is the null hypothesis?
What is the alternative hypothesis?
The type of test statistic? Z t F Chi Square
What is the value of the test statistic?
What is the p-value?
Can we reject the claim that the mean number of days before remission after treatment 1 is greater than the mean number of days before remission after the treatment 2? YES or NO
Q5: Past records suggest that the mean annual income, μ1 of teachers in state of Texas is greater than or equal to the mean annual income, μ2, of teachers in Indiana. In a current study, a random sample of 20 teachers from Texas and an independent random sample of 20 teachers from Indiana have been asked to report their mean annual income.The data obtained are as follows.
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Annual income in dollars
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Texas
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35279, 32973, 34225, 30216, 39302, 40535, 35051, 38163, 35232, 29464, 32867, 30517, 36907, 35698, 37351, 36373, 23624, 37241, 34705, 34293
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Indiana
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41734. 39704, 45064, 44977, 41243, 30348, 42628, 30507, 29861, 47889, 27595, 38908, 32901, 29363, 35976, 44940, 50725, 36981, 42610, 30978
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The population standard deviation for mean annual income of teachers in Texas and in Indiana are estimated as 6200 and 6500, respectively. It is also known that both populations are approximately normally distributed. At the 0.10 level of significance, is there sufficient evidence to reject the claim that the mean annual income of teachers in state of Texas is greater than or equal to the mean annual income of teachers in Indiana? Perform a one-tailed test. Then fill in the table below.
Carry your intermediate computations to at least three decimal places.
What is the null hypothesis?
What is the alternative hypothesis?
The type of test statistic? Z t F Chi Square
What is the value of the test statistic?
What is the critical value at the 0.01 level of significance?
Can we reject the claim that the mean annual income of teachers from Texa is greater than or equal to the mean annual income of teachers from Indiana? YES or NO