## Question

secondary 2 | Maths

Anyone can contribute an answer, even non-tutors.

##### Nicholas

chevron_right chevron_right

I need help with question 8 and 9

Date Posted: 8 months ago
Views: 76
Cassia Ng Kai Ying
8 months ago
8a) Greatest value of x is 7 given that most number of students spend 1 hour on the computer each day (mode)

8b) mean is the sum of all hours divided by the number of students: so take 0x4 + 1x8 + 2x3 +3x5 +4x + 5x7=2.625 and solve for x

8c) Median would be the middle value (for (4+8+3+5+x+7)/2)

for x to be the smallest:
4+8+3=4+x+7

clear {{ downvoteCount * -1 }} Downvotes
1st
Q8
Date Posted: 8 months ago
clear {{ downvoteCount * -1 }} Downvotes
Q9
Date Posted: 8 months ago
Boy Mow Chau
8 months ago
For part 9(b), the question says "hence …".

When question says "hence...", we MUST use the result from the preceding part.

When question says "hence or otherwise ...", then we need not use the result from the preceding part.

Even though the answers for 9(b) are correct here, likely no marks will be awarded because did not follow the question instruction.

Correct method should be …

from 9(a),
x^2 -6x+2=(x-3)^2-7
so,
x^2-6x+2=0 implies
(x-3)^2-7=0
(x-3)^2=7
x-3=+sqrt(7) or -sqrt(7)
x=+sqrt(7)+3 or -sqrt(7)+3
x=5.65 or 0.35 (to 2 d.p.)