Question

Use logarithms table to find in standard form correct 3significant figure.

3√0.0072×(81.3)2/√23140

Answer 1

log3 = 0.47712

1/2 log 0.0072 = 1/2 log(7.2*10^-3) = 1/2 (0.85733-3) = -1.07133
log(81.3^2) = 2log81.3 = 3.82018
1/2 log23140 = 2.18218
so, your log value is
0.47712-1.07133+3.82018-2.18218 = 1.04379
10^1.04379 = 11.06089

check: 3√0.0072*81.3^2/√23140 = 11.06089