题目
You want to test at the 0.05 level of significance that the mean price of luxury cars is greater than $80,000. A random sample of 50 cars has a mean price of $88,000. The population standard deviation is $15,000. What is the alternative hypothesis?
选项
A.The population mean is greater than or equal to $80,000.
B.The population mean is less than $80,000.
C.The population mean is not equal to $80,000.
D.The population mean is greater than $80,000.
答案
D
解析
The alternate hypothesis is the statement which will be accepted if the null hypothesis is proven wrong. Therefore, we make whatever we are trying to test as the alternative hypothesis-in this case that the mean price of luxury cars is greater than $80,000, and the null hypothesis as the opposite (the mean price of luxury cars is less than or equal to $80,000). This problem is a common example of how statisticians establish hypotheses by proving that the opposite (i.e. the null hypothesis) is false.备用假设是如果原假设被证明是错误的，则将接受该陈述。 因此，我们将要尝试检验的一切作为替代假设-在这种情况下，豪华车的平均价格大于$ 80,000，而零假设则相反（豪华车的平均价格小于或等于 80,000美元）。 这个问题是统计学家如何通过证明相反的假设（即原假设）为假来建立假设的一个常见例子。