Step 1 :\( T = 42 \textrm{ min} \)
Step 2 :\( n = \frac{T}{21} = \frac{42}{21} = 2 \)
Step 3 :\( B = 8014627 \times 2^n = 8014627 \times 2^2 = 8014627 \times 4 = 32058508 \)
Step 4 :\( \textrm{Estimate in millions} = \frac{B}{10^6} = \frac{32058508}{10^6} \approx 32.06 \)