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Finding the Fourth Proportional to 768.45, 1,061.11 and 489.18

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Solution

The fourth proportional to 768.45, 1,061.11 and 489.18 is: 675.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.45 : 1,061.11 = 489.18 : x
  2. Step 2: Convert to fraction form
    768.45/1,061.11 = 489.18/x
  3. Step 3: Cross multiply
    768.45x = 1,061.11 × 489.18
  4. Step 4: Simplify right side
    768.45x = 519,073.79
  5. Step 5: Solve for x
    x = 519,073.79/768.45
  6. Step 6: Final answer
    x = 675.48

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.