Generate the following new variables: age [ use the formula: (examdate-birthdate)/365] average acuity of two eyes, one variable for years of education [You have to define a variable and replace it with 16 if the value in the variable headeduc is 1; replace it with 14 if the value in the variable headeduc is 2; replace it with 12 if the value in the variable headeduc is 3 or 4 or 5; replace it with 9 if the value in the variable headeduc is 6; replace it with 6 if the value in the variable headeduc is 7; replace it with 0 if the value in the variable headeduc is 8.] four dummies for head occupation being farmer, worker, teacher, or village leader, [Occupation codes are defined in the variable headocc as follows: headocc=1 represents farmer; headocc=2 represents worker; headocc=3 represents teacher; headocc=6 represents village leader, headocc=4 and 5 and 7 and 8 represent others.] a dummy variable for previously having glasses. This variable is one if the person had glasses before project, zero otherwise. z-score of the average of the three test scores (to do this part you first need to generate a new variable that is the average of three exam scores (lets say avetest). Then find the average and standard deviation of avetest, then generate a new variable (lets say zavetest) that is the avetest score minus the average of avetest divided by the standard deviation of avetest)