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Finding the Fourth Proportional to 667.20, 921.32 and 418.95

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Solution

The fourth proportional to 667.20, 921.32 and 418.95 is: 578.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    667.20 : 921.32 = 418.95 : x
  2. Step 2: Convert to fraction form
    667.20/921.32 = 418.95/x
  3. Step 3: Cross multiply
    667.20x = 921.32 × 418.95
  4. Step 4: Simplify right side
    667.20x = 385,986.49
  5. Step 5: Solve for x
    x = 385,986.49/667.20
  6. Step 6: Final answer
    x = 578.51

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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.