Answer Happy

1. The research report showed that the percentage of adults who smoked was 0.3, A certain research team wanted to see if the percentage of adult people who wanted to take the MRT to smoke was higher than the average level. Therefore, 8 adult people were randomly selected in front of the MRT station to understand it. Whether to smoke or not, let X represent the number of smokers among the 8 people. (a) Please write down the null hypothesis and the opposite hypothesis of this research (b) Assuming that this research team is composed of 3 students, each with different decision-making methods is as follows, please fill in the following table (a)-(i) (Note, please write the calculation process). Student 1: No matter what X, always accept the null hypothesis. Student 2: 0 SX 3 accepts the null hypothesis. Student 3: No matter what X, never accept the null hypothesis. Type I error Student 1 Student 2 (a) (d) (g) Type Il error If p=0.2 If p=0.5 (b) (c) (e) (f) (h) (0) Student 3 2. The company's chain stores have an average daily turnover of RMB 7,500 and a standard deviation of RMB 2,000. It is expected that the turnover will decrease this year. 36 chain stores are randomly selected and the average daily turnover is calculated to be RMB 6,800. Assuming the standard deviation remains unchanged, let's ask (a) With a significant level of 5%, has the average daily turnover of the chain store decreased? (b) According (a), if the actual daily turnover is 7,000 yuan, what is the value of Type Il error ? (c) Continue (b). If a and ß are reduced to half of the original at the same time, how much does the number of samples need to increase?