Answer:
286 students attended
148 non students attended
Step-by-step explanation:
Given




Solving (a): Number of students
Represent students with S and non students with N
So:
--- (1)
--- (2)
Make N the subject of formula in (1)

Substitute 434 - S for N in (2)

Open Bracket

Collect Like Terms


Divide through by -2

<em>Hence; 286 students attended</em>
Solving (b):
Recall that



<em>148 non students attended</em>
The answer is B. Multiply
Answer: mean=87, median=87.5 and range=18
Step-by-step explanation:
Mean:
First add all the numbers
78+95+77+92+87+79+94+86+88+94 = 870
Then you divide the answer by counting the numbers
870÷10
=87
Median:
First arrange the numbers in ascending order (from smallest to largest)
77, 78, 79, 86, 87, 88, 92, 94, 94, 95
pick the two middle numbers which is 87 and 88
then you do 
= 175÷2
= 87.5
range = Largest number - smallest number
= 95-77
= 18
7.29 but if you have to round up, 8 days
Y : x
14 : 18
31 : x
18*31/14=x
39.85714286
ANSWER
x=39.86