Using interpolation estimate the business done in 1985 from the following data

Year	1982	1983	1984	1986
Business done (in lakhs)	150	235	365	525

Find the missing figures in the following table

x	0	5	10	15	20	25
y	7	11	-	18	-	32

Using Lagrange’s interpolation formula find a polynomial which passes through the points (0, –12), (1, 0), (3, 6) and (4,12).

If u₀ = 560, u₁ = 556, u₂ = 520, u₄ = 385, show that u₃ = 465

The area A of circle of diameter ‘d’ is given for the following values

D	80	85	90	95	100
A	5026	5674	6362	7088	7854

Find the approximate values for the areas of circles of diameter 82 and 91 respectively