Allen’s hummingbird (Selasphorus satin) has been studied by zoologist Bill Alther. Suppose a small group of 16 Allen’s hummingbirds has been under study in Arizona. The average weight for these birds is x= 3.00 grams. Based of previous studies, we can assume that the weights of Allen’s hummingbirds have a normal distribution, with o= 0.30 gram. When finding 80% confidence interval, what is the critical value for confidence level? (Give your answer to two decimal places.) Upper, lower, and margin of error. Find the minimal sample size for an 80% confidence level with a maximal margin of error= 0.16 for the mean weights of the hummingbirds. (Round your answer to a whole number)
