**GlassRI 01:
Grouping refractive index data by SKM2 using Excel
**

Assume that eight fragments have been recovered from a suspect. These fragments have refractive index, RI, values (each the average of several GRIM measurements) given by:

1.52433 |
1.52427 |
1.52381 |
1.52397 |
1.52396 |
1.52426 |
1.52400 |

The
control samples submitted have RI values with a
standard deviation = 4.16×10^{-05}

Use the SKM2 algorithm to check for sub-groups within the data by calculating appropriate values of l

Use the standard deviation of the control as an estimate for the standard deviation of the recovered group.

Video Answer:
l^{*}
= 177, 17.3, 3 groups