The line through P(5, 3) intersects y-axis at Q.
(i) Write the slope of the line.
(ii) Write the equation of the line.
(iii) Find the co-ordinates of Q.
(i) Since the line make 45 with positive direction of x-axis,
Therefore slope (m) = tan 45° = 1
(ii) Equation of line, using point-slope is
y - y1 = m(x - x1)
Thus, y = x - 2
(iii) Since Q is a point on y-axis, its x-coordinate is zero.
Putting x = 0 in the equation of line, we get
y = –2
Hence the point Q is (0, –2).
The following distribution represents the height of 160 students of school.
Height (in cm) | No. of Students |
140 – 145 | 12 |
145 – 150 | 20 |
150 – 155 | 30 |
155 – 160 | 38 |
160 – 165 | 24 |
165 – 170 | 16 |
170 – 175 | 12 |
175 – 180 | 8 |
Draw an ogive for the given distribution taking 2 cm = 5 cm of height on one axis and 2 cm = 20 students on the other axis. Using the graph, determine:
(i) The median height.
(ii) The interquartile range.
(iii) The number of students whose height is above 172 cm.