Q29 of 46 Page 1

If the mean of the following frequency distribution is 62.8, then find the missing frequency x :



Now,



⇒62.8 (40 + x) = 2640 + 50x


⇒2512 + 62.8x = 2640 + 50x


⇒ 62.8x – 50x = 2640 – 2512


⇒ 12.8x = 128


⇒ x = 10


More from this chapter

All 46 →
27

Draw a circle of radius 3 cm. Take a point A on its extended diameter at a distance of 7 cm from its centre. Draw two tangents to the circle from A.

 28

If tan x = n tan y and sin x = m sin y, prove that


OR


If x sin3θ + y cos3θ = sinθ cosθ and x sinθ = y cosθ, prove that x2 + y2 = 1.


 30

The radii of the circular ends of the frustum of a cone of height 45 cm, are 28 cm and 7 cm. Find its volume and curved surface area.

 6

Which term of the A.P. 4, 7, 10, ... is 64 ?