1. **State the problem:** Chelsea runs north 0.75 mile, then west 1 mile, and finally runs straight home. We need to find the total distance she runs each week (5 weekdays). 2. **Identify the shape and formula:** The path forms a right triangle with legs 0.75 mile and 1 mile. The straight line home is the hypotenuse $c$. 3. **Use the Pythagorean theorem:** $$c = \sqrt{0.75^2 + 1^2}$$ 4. **Calculate the squares:** $$0.75^2 = 0.5625$$ $$1^2 = 1$$ 5. **Sum the squares:** $$0.5625 + 1 = 1.5625$$ 6. **Find the hypotenuse:** $$c = \sqrt{1.5625} = 1.25$$ 7. **Calculate total distance for one day:** $$0.75 + 1 + 1.25 = 3$$ miles 8. **Calculate total distance for the week (5 days):** $$3 \times 5 = 15$$ miles **Final answer:** Chelsea runs a total of 15 miles each week.