r calculate coefficient by factor r multiply two coefficients in regression how do you combine dummies in r how do you find the coefficient for a variable in r how do you combine two factors in r how to find a coefficient in r calculate factor for regression how do you multiply two factors in r what is the product of dummy variables in r r calculate coefficient based on time how do you find product of a factor in r how to calculate coefficients using dummy variables does factor in r work calculate coefficients for the first dummy variable how to multiply factors in r calculate the coefficient of a dummy variable in regression how do coefficients work in regression what r function do you use to find the product of two dummy variables? how to calculate product of two factors how to make factor in r