Use graph (squared paper) to solve this question.

(i) Draw the ogive for the following frequency distribution.

Use your graph to find :

(ii) the median

(iii) the number of students who secured more than 75% marks.

In the given figure, ∠CED = ∠CAB.

(i) Show that :

△CED is similar to triangle CAB.

(ii) Find DE.

If M is the mean of six natural numbers x₁, x₂, x₃, x₄, x₅ and x₆. Show that :

(x₁ - M) + (x₂ - M) + (x₃ - M) + (x₄ - M) + (x₅ - M) + (x₆ - M) = 0