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Finding the Fourth Proportional to 645.68, 891.11 and 409.70

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Solution

The fourth proportional to 645.68, 891.11 and 409.70 is: 565.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.68 : 891.11 = 409.70 : x
  2. Step 2: Convert to fraction form
    645.68/891.11 = 409.70/x
  3. Step 3: Cross multiply
    645.68x = 891.11 × 409.70
  4. Step 4: Simplify right side
    645.68x = 365,087.77
  5. Step 5: Solve for x
    x = 365,087.77/645.68
  6. Step 6: Final answer
    x = 565.43

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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.