An analysis of the grades on the first test in history 101 revealed that they approximate a normal curve with a mean of 75 and a standard deviation of 8. the instructor wants to award the grade of a to the upper 10 percent of the test grades. what is the dividing point between an a and a b grade

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.

what are you doing do you need examples of variable questions?

step-by-step explanation:

5a-1=9               bring the one over the =

5a=10                     divide by your variable

a=2

brainliest? ?

here try this one

3a-24=0