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Finding the Fourth Proportional to 721.45, 1,081.94 and 288.50

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Solution

The fourth proportional to 721.45, 1,081.94 and 288.50 is: 432.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.45 : 1,081.94 = 288.50 : x
  2. Step 2: Convert to fraction form
    721.45/1,081.94 = 288.50/x
  3. Step 3: Cross multiply
    721.45x = 1,081.94 × 288.50
  4. Step 4: Simplify right side
    721.45x = 312,140.95
  5. Step 5: Solve for x
    x = 312,140.95/721.45
  6. Step 6: Final answer
    x = 432.66

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.