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Finding the Fourth Proportional to 489.12, 732.40 and 407.70

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Solution

The fourth proportional to 489.12, 732.40 and 407.70 is: 610.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.12 : 732.40 = 407.70 : x
  2. Step 2: Convert to fraction form
    489.12/732.40 = 407.70/x
  3. Step 3: Cross multiply
    489.12x = 732.40 × 407.70
  4. Step 4: Simplify right side
    489.12x = 298,599.48
  5. Step 5: Solve for x
    x = 298,599.48/489.12
  6. Step 6: Final answer
    x = 610.48

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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.