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Finding the Fourth Proportional to 614.40, 920.85 and 419.40

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Solution

The fourth proportional to 614.40, 920.85 and 419.40 is: 628.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    614.40 : 920.85 = 419.40 : x
  2. Step 2: Convert to fraction form
    614.40/920.85 = 419.40/x
  3. Step 3: Cross multiply
    614.40x = 920.85 × 419.40
  4. Step 4: Simplify right side
    614.40x = 386,204.49
  5. Step 5: Solve for x
    x = 386,204.49/614.40
  6. Step 6: Final answer
    x = 628.59

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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.