7.4.5. The following stem-and-leaf plot gives the weight in kilograms of 30 stalks of an experimental variety of plantain fruit that has been genetically altered to contain a greater level of protein: kg kg/10 9 8 8 246 7 3578 6 01378 5 123478 8 4 12467 3 01357 a. Compute s 2. b. Find a 95% confidence interval for of. c. Perform a test of hypothesis at the 5% level of significance to determine whether or not this sample came from a population that has a variance of 3.0. d. Find a 95% confidence interval for u using s to approximate of