I am working on computing the scaled efficiency in question (3.b), and I am a bit confused about the data available in the table.

Namely, I am using the process described in the lecture notes (pages 1-69–1-72) to compute $n_4, n_8$, and $n_{16}$, which are required in the computation of scaled efficiency.

However, given that matrix-matrix multiplication has cubic complexity, I end up having to take the cubic root of $p$, which means I end up with values for $n_4, n_8$, etc. which are not in the table.

Should I simply approximate to the closest values in the table, or is there something else that I may be missing?

Alternatively, if we were to follow the example from pages 1-78 and 1-79, is it sufficient to only provide an analytical formula for the resulting efficiency?

Thank you,

Andrei