Answer:
. In other words, there number of girls is
.
Step-by-step explanation:
The average of a number of measurements is equal to the sum of these measurements over the number of measurements.
.
Rewrite to obtain:
.
For this question:
.
.
Therefore:
.
On the other hand, there are
boys and girls in total. Using the formula for average:
.
From the question, this average should be equal to
. In other words:
.
Solve this equation for
to obtain:
.
.
.
In other words, the number of girls here is
.
Answer:
100
Step-by-step explanation:
Ratio is a fraction, so ratio of boys to girls would be written as [let boys be "b" and girls be "g"]:

Also, there are 250 more girls than boys, so we can write:
g = 250 + b
Lets substitute this into "g" of the ratio we wrote and cross mulitply and solve for b:

The number of boys = 100
Answer:
Im not fully sure but I think it is negative 2 and negative 3
Step-by-step explanation:
AD ≅ BC, Given
∠BCD ≅ ∠ADC, Given
CD ≅ CD, Reflexive property
ΔBCD ≅ ΔADC, SAS congruence
∠BDC ≅ ∠ACD, CPCTC
ΔECD is an isosceles triangle, definition of isosceles
DE ≅ CE, properties of isosceles triangles