Question

find answer of question 8 that is follow question 5

5. According to an official statement released by the state of California, the average height of a Redwood tree in California is 350 ft. To assess this claim, a scientist collects a sample of 50 randomly chosen Redwood trees in California. She finds that the average heights in her sample is 355 ft. We assume it is known that the population standard deviation is 42 ft. (a) Conduct a hypothesis test to assess whether the true average height is 350 ft or if it higher. Use a=0.1. (b) Find the p-value for the sample. 6. Two baby-food manufacturers are competing, and manufacturer of brand A believes that their brand causes more weight gain in infants than manufacturer of brand B. A sample of size 15 fed their babies brand A for two months, and saw an average weight gain of 36.93 ounces, with a standard deviation of 4.23 ounces. A sample of size 25 fed their babies brand B and saw an average weight gain of 31.36 ounces with a standard deviation of 3.35 ounces. Assume the d. f. = 24. (a) Find the lower bound for the 95% confidence interval for the difference in average weight gain between the two baby food brands. (b) Find the upper bound for the 95% confidence interval for the difference in average weight gain between the two baby food brands. (c) Interpret your interval from (a,b) in terms of the problem. (d) Does your interval suggest one brand of baby food causes more weight gain than the other on average? (e) If the sample sizes increased to 100, but everything else remained constant, would our interval widen or narrow? 7. A group of paramedics does not believe that the average number of calls in the morning, afternoon and night shifts are equal. They counted the number of calls over 7 days, and found the following: Morning Afternoon Night 9 2 .57 3.71 4.29 $ 0.98 1.11 1.38 n7 Let Morning = group 1, Afternoon = group 2, and Night = group 3 (a) Calculate SSB (b) Calculate SSW (c) Calculate de (d) Calculate dfw (e) Calculate MSB. (f) Calculate MSW (6) Calculate the F test statistic. 8. Continue with Problem 5 (the paramedic problem). Assume a = 0.01 (a) State the null and alternative hypothesis mathematically. (b) State the null and alternative hypothesis in terms of the problem. (c) Calculate the range for the p-value. (d) Do you reject or fail to reject the null hypothesis? (e) Interpret your conclusion in terms of the problem. (f) Interpret a Type I error in terms of the problem.

Answer 1

Bla) Hoi l= 350 Hi uz 350 6 Ho: Average height of a H: verage height of a Redwood tro in California is 350 ft. Average height of a Redwood tree in California is not equal to 350 ft. Average height of a c I2 1 = 15-le 1 I 5/5nT = 355-356 427150 = 0.8418 Z 0.3999 p value =

Page No. 0 . 01< علممععممه :و عععهعههللنمهعمم e) Thus we can conclude a Redwood tree in that average height of California is 350 ft f) A type 1 error would to be when we conclude that average height of a Redwood tree in California is not equal to 350 ft but when actually it is 350 ft.