sample 20 c6 c10
sample 5 c7 c11
let c14(k1)=mean(c10)
let c15(k1)=mean(c11)
let c16(k1)=mean(c10)-mean(c11)
let c17(k1)=std(c10)
let c18(k1)=std(c11)
let k1=k1+1