Identify the symbols used for each of the following: (a) sample standard deviation; (b) population standard deviation; (c) sample variance; (d) population variance. a. the symbol for sample standard deviation is▼ss squaredsigmasigma squared. b. the symbol for population standard deviation is▼ss squaredsigmasigma squared. c. the symbol for sample variance is▼ss squaredsigmasigma squared. d. the symbol for population variance is▼ss squaredsigmasigma squared.