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Finding the Fourth Proportional to 988.10, 1,481.80 and 439.30

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Solution

The fourth proportional to 988.10, 1,481.80 and 439.30 is: 658.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    988.10 : 1,481.80 = 439.30 : x
  2. Step 2: Convert to fraction form
    988.10/1,481.80 = 439.30/x
  3. Step 3: Cross multiply
    988.10x = 1,481.80 × 439.30
  4. Step 4: Simplify right side
    988.10x = 650,954.74
  5. Step 5: Solve for x
    x = 650,954.74/988.10
  6. Step 6: Final answer
    x = 658.79

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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.