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Finding the Fourth Proportional to 645.45, 891.32 and 470.49

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Solution

The fourth proportional to 645.45, 891.32 and 470.49 is: 649.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.45 : 891.32 = 470.49 : x
  2. Step 2: Convert to fraction form
    645.45/891.32 = 470.49/x
  3. Step 3: Cross multiply
    645.45x = 891.32 × 470.49
  4. Step 4: Simplify right side
    645.45x = 419,357.15
  5. Step 5: Solve for x
    x = 419,357.15/645.45
  6. Step 6: Final answer
    x = 649.71

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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.