Question

a=4,2 cu ponderea 7
b=3,5(3) cu ponderea 3
media aritmetică ponderată=?
dau coroană repede

Answer 1

3.5(3)=3 intregi si (53-5)/90=3+48/90=318/90=159/45
4.2=42/10=21/5
Media ponderata=(21/5*7+159/45*3)/(7+3)=(21*7/5+159*3/45)/10=(147/5+477/45)/10=(1323/45+477/45)/10=(1800/45)/10=40/10=4