Answer:
Step-by-step explanation:
From the information given,
Mark: 6,7,8,9,10
frequency:5,4,7,10,4
a) Range = highest mark - lowest mark
Range = 10 - 6 = 4
b) The number of students in the group is the sum of the frequency. Therefore,
Number of students = 5 + 4 + 7 + 10 + 4 = 30 students
c) Mean mark = (mark × frequency)/total frequency
[(6 × 5) + (7 × 4) + (8 × 7) + (9 × 10) + 10 × 4)]/ 30
Mean mark = (30 + 28 + 56 + 90 + 40)/30 = 244/30
Mean mark = 8.1
By the table, it seems to be that f = 1/2x
Answer:
158.76 cm²
Step-by-step explanation:
Quadrilateral ABCD is composed of 2 right triangles
Construct the line BD, then
Δ ABD and Δ BCD are the 2 right triangles.
The area (A) of a triangle is calculated using
A = 
bh ( b is the base and h the perpendicular height )
Δ ABD with b = 18 and h = 7.5
A = × 18 × 7.5 = 9 × 7.5 = 67.5 cm²
Δ BCD with b = 15.6 and h = 11.7
A = × 15.6 × 11.7 = 7.8 × 11.7 = 91.26 cm²
Thus
area of ABCD = 67.5 + 91.26 = 158.76 cm²
110 - 4x = x + 10
100 = 5x
x = 20
2x - 20 = 3y - 10
Plug in x
2(20) - 20 = 3y - 10
40 - 20 = 3y - 10
20 = 3y - 10
30 = 3y
y = 10
