题目:

1. The ABC Company claims that the batteries it produces have useful life of more than 100 hours, with a known standard deviation (of population) of 20 hours. A test is undertaken to test the validity of this claim. Please set of hypotheses for this test?

2. In hypothesis testing, the hypothesis which is assumed to be true is called?

然后请各位高手解释一下这些答案的原理好吗? 谢谢!!!!!

还有我想请问一下,哪里可以找到一些关于Hypothesis Testing &Confidence Intervals 概念的题目, 因为我对概念比较模糊,谢谢了!!!!