Again, we need both the graph and the pie chart. The simplest approach here is this: we are taking percents of the same whole; therefore, the difference in the two amounts is the same as the difference in the percents, multiplied by the whole. The whole here is the number of 1970 domestic-ship inspections, or 13 thousand ships. The percents are 23 percent for domestic passenger ships and 16 percent for domestic tugboats; giving us a difference of $\(23-16\)$ or 7 percent. Therefore, we want 7 percent of 13 thousand. Again, the choices are fairly close together, so let's just multiply the numbers rather than estimate.

$$
\(7 \% \times 13,000=\frac{7}{100} \times 13,000=7 \times 130=910\)
$$