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Finding the Fourth Proportional to 645.87, 891.04 and 478.23

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Solution

The fourth proportional to 645.87, 891.04 and 478.23 is: 659.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.87 : 891.04 = 478.23 : x
  2. Step 2: Convert to fraction form
    645.87/891.04 = 478.23/x
  3. Step 3: Cross multiply
    645.87x = 891.04 × 478.23
  4. Step 4: Simplify right side
    645.87x = 426,122.06
  5. Step 5: Solve for x
    x = 426,122.06/645.87
  6. Step 6: Final answer
    x = 659.76

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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.