1. **Stating the problem:** We have a scatter plot showing the number of calls $n$ Pete made each month and the corresponding cost $b$ in dollars. We need to find the equation of the line of best fit in the form $$b = mn + c$$ where $m$ is the slope and $c$ is the y-intercept. 2. **Finding the slope ($m$):** The slope represents the average cost per extra call. From the graph, observe two points on the line of best fit, for example $(0,10)$ and $(60,60)$. 3. Use the slope formula: $$m = \frac{b_2 - b_1}{n_2 - n_1} = \frac{60 - 10}{60 - 0} = \frac{50}{60} = \frac{5}{6}$$ 4. **Finding the intercept ($c$):** The line crosses the cost axis at $b=10$ when $n=0$, so $$c = 10$$ 5. **Equation of the line:** $$b = \frac{5}{6}n + 10$$ 6. **Average cost per extra call:** The slope $m = \frac{5}{6}$ dollars per call. To convert to cents: $$\frac{5}{6} \times 100 = 83.33 \text{ cents}$$ 7. **Estimate cost for 33 calls:** Substitute $n=33$ into the equation: $$b = \frac{5}{6} \times 33 + 10 = \frac{5 \times 33}{6} + 10 = \frac{165}{6} + 10 = 27.5 + 10 = 37.5$$ So, Pete would pay $37.5$ dollars. **Final answers:** - Equation: $$b = \frac{5}{6}n + 10$$ - Average cost per call: 83.33 cents - Estimated cost for 33 calls: 37.5 dollars