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Finding the Fourth Proportional to 615.54, 921.48 and 420.73

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Solution

The fourth proportional to 615.54, 921.48 and 420.73 is: 629.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    615.54 : 921.48 = 420.73 : x
  2. Step 2: Convert to fraction form
    615.54/921.48 = 420.73/x
  3. Step 3: Cross multiply
    615.54x = 921.48 × 420.73
  4. Step 4: Simplify right side
    615.54x = 387,694.28
  5. Step 5: Solve for x
    x = 387,694.28/615.54
  6. Step 6: Final answer
    x = 629.84

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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.