l (a) In an investigation of toxins produced by molds that infect corn crops, a biochemist prepares extracts of the mold culture with organic solvents and then measures the amount of the toxic substance per gram of solution. From 10 preparations of the mold culture, the following measurements of the toxic substance (in milligrams) are obtained: 1.5,1.1,1.9,1.7,2.3,2.4,1.9,1.9,2.2,2.3 Find a 90% condence interval for the mean weight (in milligrams) of toxic substance per gram of mold culture in the sampled population. (b) Which of the following statements is true regarding part (a)? confidence interval |:| enter your answer in the form a,b (numbers correct to 2 decimals) (A) The population must be normal. (B) The population standard deviation 0 must be known. (C) The population does not need to be normal. (D) The population must follow a t-distribution. (E) The population mean must be inside the condence interval