10 students averaged 80, so the sum of their scores was (10 x 80) = 800
20 students averaged 89, so the sum of their scores was (20 x 89) = 1,780
All together, the sum of all 30 scores was (800 + 1,780) = 2,580
30 students totaled 2,580, so their average was (2,580 / 30) = <em> 86</em> .
Answer:
1) The perpendicular bisector of the given line segment is 90 degrees
Step-by-step explanation:
I don't know the second one
Answer:
time = 28 years
Step-by-step explanation:
Given,
principal amount = $10,000
rate = 4%
total amount = $30,000
According to compound interest formula
where, A = total amount
P = principal amount
r = rate
t = time in years
so, from the question we can write,
by taking log on both sides, we will get
=> log3 = t.log(1.04)
=> t = 28.01
So, the time taken to get the amount from 10000 to 30000 is 28 years.
Answer:
8cm
Step-by-step explanation:
x is similar to the side 12cm.
We know the second triangle is rotated counter-clockwise from the first because similar triangles have the same angle measurements.
Since the angle in the first triangle between 9cm and 15cm is 53°, it can't be similar to the angle between x and the hypotenuse in the second triangle.
Find the scale factor:
Triangle 1/Triangle 2
Divide two similar sides.
6/9 = 2/3
Multiply the scale factor by the similar side to find x.
x = 12*(2/3)
x = 8
Answer:
y=2x+14
Step-by-step explanation:
y-y=m(x-x1)
y-6=2(x-(-4))
y-6=2x+8
+6 +6
y=2x+14
