Answer:
495 combinations of 4 students can be selected.
Step-by-step explanation:
The order of the students in the sample is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

How many combination of random samples of 4 students can be selected?
4 from a set of 12. So

495 combinations of 4 students can be selected.
Answer:
y = 2x + 4
Step-by-step explanation:
First find 2 points on the line to determine slope.
(0, 4) and (2, 8)
Slope = 
y = 2x + b
b = y - intercept
b = 4
y = 2x + 4
Answer:
x=4
Step-by-step explanation:
tangent lines from the same point to a circle are congruent in length, so we can say that
5x+8 = 8x-4
5x -5x +8 = 8x - 5x -4
8 = 3x - 4
8+4 = 3x -4 + 4
3x = 12
3x/3 = 12/3
x=4
The average cost in 1990 is <span>$12,841.</span>
Answer:
Option c is correct !!
Step-by-step explanation:
[ Refer to the attachment ]
As y = mx + c is an equation to represent the straight line ; we equate the given line with this equation !!
Where m is slope of the line
and c is y intercept !!
We get , m = -3/2 and c = 4
Also, two perpendicular lines follows the equation :-

Where m nth is slope of nth line !!