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Finding the Fourth Proportional to 489.10, 732.85 and 420.30

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Solution

The fourth proportional to 489.10, 732.85 and 420.30 is: 629.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.10 : 732.85 = 420.30 : x
  2. Step 2: Convert to fraction form
    489.10/732.85 = 420.30/x
  3. Step 3: Cross multiply
    489.10x = 732.85 × 420.30
  4. Step 4: Simplify right side
    489.10x = 308,016.86
  5. Step 5: Solve for x
    x = 308,016.86/489.10
  6. Step 6: Final answer
    x = 629.76

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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.