1. Dave's Automatic Door installs automatic garage door openers. The following list indicates the number of minutes needed to install a sample of 10 door openers: 28, 32, 24, 46, 44, 40, 54, 38, 32, and 42 (a) Calculate the sample mean, median, and mode by "hand" using the formulas. Do not use the Excel functions. (b) Calculate the sample variance, standard deviation, and range by "hand" using the formulas. Do not use the Excel functions.