Following are the results of a sieve analysis:

Sieve No.	Percent finer
4	100
10	90
20	80
40	70
60	40
80	29
100	19
200	10
Pan	-

(a) Plot the grain-size distribution curve for this sample.
(b) Determine D₁₀, D₃₀, and D₆₀.
(c) Calculate the uniformity coefficient, C_u.
(d) Calculate the coefficient of gradation, C_c.