1. **Problem Statement:** Calculate the Marginal Utility (MU) from the Total Utility (TU) data given for each unit and explain the behavior of TU and MU. 2. **Formula:** Marginal Utility is calculated as the change in Total Utility divided by the change in quantity: $$MU = \frac{\Delta TU}{\Delta Q} = \frac{TU_{n} - TU_{n-1}}{Q_{n} - Q_{n-1}}$$ 3. **Calculations:** - For unit 1: $$MU = \frac{7 - 0}{1 - 0} = 7$$ - For unit 2: $$MU = \frac{13 - 7}{2 - 1} = 6$$ - For unit 3: $$MU = \frac{18 - 13}{3 - 2} = 5$$ - For unit 4: $$MU = \frac{22 - 18}{4 - 3} = 4$$ - For unit 5: $$MU = \frac{25 - 22}{5 - 4} = 3$$ - For unit 6: $$MU = \frac{27 - 25}{6 - 5} = 2$$ - For unit 7: $$MU = \frac{28 - 27}{7 - 6} = 1$$ - For unit 8: $$MU = \frac{28 - 28}{8 - 7} = 0$$ - For unit 9: $$MU = \frac{27 - 28}{9 - 8} = -1$$ - For unit 10: $$MU = \frac{25 - 27}{10 - 9} = -2$$ 4. **Explanation:** - Marginal Utility decreases as more units are consumed, showing the law of diminishing marginal utility. - Total Utility increases initially, reaches a maximum at unit 8, then starts to decline. - When MU is zero, TU is at its peak. - Negative MU indicates TU is decreasing. 5. **Summary:** - The MU curve slopes downward, crossing zero at unit 8. - The TU curve rises, peaks, then falls. - This behavior illustrates diminishing returns. **One word to describe the phase:** Diminishing