To find the point estimate of the difference between population mean.
Injuries to Major league Baseball players have been increasing in recent years. For the period of 1992 to 2001, league expansion caused major league rosters to increase 15%. However the number of players being put on the disabled list increased 32% over the same period. A research question addressed whether MLB players being put on the disabled list are on the list longer in 2001 than players put on the disabled list a decade earlier.
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2001 season
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1992 season
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sample size
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n1= 45
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n2=38
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sample mean
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x1= 60 days
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x2 = 51 days
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sample standard deviation
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s1= 18 days
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s2 = 15 days
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a) Using the population mean number of days a player on the disabled list, formulate null and alternative hypothesis that can be used to test the research question.
b) Assume that the following data apply:
What is the point estimate of the difference between population mean, number of days on the disabled list for 2001 compared to 1992? What is the percentage increase in the number of days on the disabled list?
c) Use a= .01. What is your conclusion about the number of days on the disabled list? What is the p value?
d) Do these data suggest that the MLB should be concerned about the situation?