How can I calculate my grade

Lecture grade=(Lowest test grade 10%)+(Remaining test grades 30% each)

& my grades are 95, 88, & 72.. How would I go about doing this with that formula?

.72 * .1 + .88 * .3 + .95 * .3 = .621

.621 / .7 = 0.88714285714285714285714285714286
you have an 88.71% for your lecture grade which is 70% of the class

there is another 30% of the class to take
the highest grade you can get in the class is .621 + .3 = 92.1%
the lowest grade you can get is 62.1%

grade =[10/100 x 72] + [30/100 x 95] + [30/100 x 88] = 62.1

i think u left one grade mark.....95 , 88 ,72 and one more will be there