GEOTECH. ENG'g (particle-size distribution curve)

in solving for UNIFORMITY COEFFICIENT (Cu = D60/D10)

what if D10 or 10% finer doesn't exis in the particle size distribution curve? How can i solve this? Help please, thank you.

GIVEN:

Diameter(mm) % passing
4.76 100
2.38 90
2.00 77
0.84 59
0.42 51
0.25 42
0.149 35
0.074 33

You can tell a lot about the mechanical properties of the soil according to the value of the effective size D10. However, the sieve analysis is higher than 10%. In this case, the properties of this soil cannot be defined according to uniformity coefficient or anything that involves D10. You need to determine the Atterberg limits of this soil and find its indices like liquidity index and plasticity index then plot the result into USCS chart.