Answer:
Point Form:
(
5
,
2)
Equation Form:
x
=
5
,
y
=
2
Step-by-step explanation:
Solve for the first variable in one of the equations, then substitute the result into the other equation.
Divide 48 by 3, for every three 8th graders, there is one 7th grader in choir
48÷3=16
There's 16 7th graders in choir !!
Answer: 68
Step-by-step explanation:
Formula for sample size when prior estimate of population proportion (p) is available: 
, where z*= critical-value.
E= Margin of error.
Let p be the population proportion of trees are infected with the citrus red mite.
As per given , we have

E= ± 0.08
The critical z-value corresponding to 90% confidence level = z*=1.645
Substitute all the values in the above formula , we get
Required sample size :

[Rounded to next integer.]
Thus, the minimum sample size should be taken =68