QUESTION 1

Suppose that 20% of the fields in a given agricultural area are infested with the sweet potato whitefly. One hundred fields in this area are randomly selected, and 45 are found to be infested with whitefly. (a) Assuming that the experiment satisfies the conditions of the binomial experiment, do the data indicate that the proportion of infested elds is greater than expected? Use the pavalue approach, and test using a 5% significance level. State the null and alternative hypotheses. O HO: p = O Zyersus Ha p 0.2 0 HE: D a 0.2 versus Ha: p = 0.2 :p0.2 Find the p-value. (Round your answer to four decimal places.) State your conclusion. 0 Since the prvalue is greater than 0.05, H0 is not rejected. There is insufficient evidence to indicate that the proportion of infested fields is larger than expected 0 Since the prvalue is greater than 0.05, H0 is rejected. There is insufficient evidence to indicate that the proportion of infested fields is larger than expected. 0 Since the p-value is less than 0.05, H0 is not rejected. There is sufficient evidence to indicate that the proportion of infested fields is larger than expected. 0 Since the prvalue is less than 0.05, HD is rejected. There is sufficient evidence to indicate that the proportion of infested fields is larger than expected. (b) If the proportion of infested fields is found to be significantly greater than 0.20, why is this of practical significance to the agronomist? What practical conclusions might she draw from the results? 0 The agronornist may determine that because the proportion of infested fields was unusual, no action needs to be taken. 0 The agronornist may determine that an unusually low proportion of infested fields might indicate a contagious disease 0 The agronomist may determine that an unusually high proportion of infested fields indicates a contagious disease. 0 The agronornist may determine that because the proportion of infested fields was not unusual, the sampling method was not random. 0 The agronomist may determine that because the proportion of infested fields was not unusual, no action needs to be taken. You may need to use the appropriate appendix table or technology to answer this question. An experimenter has prepared a drug-dose level that he claims will induce sleep for at least 80% of people suffering from insomnia. After examining the dosage we feel that his claims regarding the effectiveness of his dosage are inflated. In an attempt to disprove his claim, we administer his prescribed dosage to 70 insomniacs and observe that 52 of them have had sleep induced by the drug close. Is there enough eVidence to refute his claim at the 5% level of significance7 State the null and alternative hypotheses. O HO: p = 0.80 versus Ha: p > 0.80 : p 0.80 O HO: p = 0.80 versus Ha: p |: z