How much of the tunnel was completed 26 days after the tbm was introduced?

The complete question is shown in the figure attached with:

Using the given table we can find a linear function relating the Tunnel Length in feet to the TBM use in days.

Let x represent the number of TBM use and y represent the length of tunnel in feet. In 6 days tunnel length was 410 feet and in 45 days tunnel length was 2165 feet. The slope (m) can be calculated as:



This means slope is 45. Now using the slope and the point (6, 410) we can set up the equation using point slope form.



Using this equation we can find the number of feet of tunnel completed in 26 days by substituting x = 26.

So,

y = 45(26) + 140 = 1310 feet

This means 1310 feet of tunnel was completed in 26 days after the TBM was introduced.