Daily Puzzle #63

A geotechnical engineer is investigating how soil bearing capacity varies with depth. Soil tests at 6 different depths yield the following summary statistics.

A simple linear regression of bearing capacity ($y$, kPa) on depth ($x$, m) yields the following:

• $\bar{x} = 5$, $\bar{y} = 85$
• $b_1 = 9.5$ (slope)

Compute the intercept $b_0$ of the regression line $\hat{y} = b_0 + b_1 x$.

Round to four significant figures.