Consider the following frequency distribution. Class 2 up to 4 4 up to 6 6 up to 8 8 up to 10 Frequency 27 53 87 27 a. Calculate the population mean. (Round your answer to 2 decimal places.) Population mean b. Calculate the population variance and the population standard deviation. (Round intermediate calculations to at least 4 decimal places and final answers to 2 decimal places.) Population variance Population standard deviation