The given data is
Scores: 90-99 80-89 70-79 60-69 50-59
Students: 3 7 12 4 4
Because we are to take the middle value for each group.
Therefore the total score is
Sx = 3*94.5 + 7*84.5 + 12*74.5 + 4*64.5 + 4*54.5 = 2245
The number of students is 3+7+12+4+4 = 30
The mean is
m =2245/30 = 74.833
Calculate (Sx - m)²
(Sx - m)² = 3*(94.5-74.833)² + 7*(84.5-74.833)² + 12*(64.5-74.833)²
+ 4*(64.5-74.833)² + 4*(54.5-74.833)² = 3896.7
Calculate the standard deviation
s = √(3896.7/29) = 11.592
Answer:
mean = 74.83
std. deviation = 11.59
The answer is 200.
The reason is because if you have 50 teachers, and that is 1/4 of the number of total teachers, then you would multiply the number of basic math teachers by four.
Division property of equality
Answer:
sure the first one for -2x-5y=16 is x is (-8,0) and y is (0,-16/5)
the second one for 2x-3y=-16 for x is (8,0) and y is (0, 16/3)
the third one for -5x+2y=11 for x is NONE and y is 8
the last one (thank god) for -3x+4y=-13 for x is (13/-3,0) and y is (0, 13/4)
Step-by-step explanation:
X= one angle
90-x= complementary angle ( complementary angles adds up to 90 degrees)
x=90-x+42.6
x=-x+132.6(combine like terms)
x+x=-x+132.6+x(add x on both sides)
x=66.3(divide each side by 2)
90-66.3=2
one angle is 42.6 complentary angle is 88 degrees
