The problem asks us to complete a ratio table. The table has two columns. The first few entries are: 10 : 13 20 : 26 30 : 39 40 : ? ? : 91

1. Problem Description

The problem asks us to complete a ratio table. The table has two columns. The first few entries are:

10 : 13

20 : 26

30 : 39

40 : ?

? : 91

2. Solution Steps

First, we observe the relationship between the numbers in the two columns.

From 10 to 13, 20 to 26, and 30 to 39, we can see that the ratio between the first and second column is $\frac{10}{13} = \frac{20}{26} = \frac{30}{39}$.

In fact, the ratio is $\frac{10}{13}$.

We can write this as $\frac{x}{y} = \frac{10}{13}$ or $y = \frac{13}{10}x$.

For the fourth row, we are given $x=40$. So, $y = \frac{13}{10} * 40 = 13 * 4 = 52$.

For the last row, we are given $y=91$. So, $91 = \frac{13}{10}x$.

$x = \frac{91 * 10}{13} = \frac{910}{13} = 70$.

3. Final Answer

52

70