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Finding the Fourth Proportional to 898.20, 1,239.57 and 499.89

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Solution

The fourth proportional to 898.20, 1,239.57 and 499.89 is: 689.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    898.20 : 1,239.57 = 499.89 : x
  2. Step 2: Convert to fraction form
    898.20/1,239.57 = 499.89/x
  3. Step 3: Cross multiply
    898.20x = 1,239.57 × 499.89
  4. Step 4: Simplify right side
    898.20x = 619,648.65
  5. Step 5: Solve for x
    x = 619,648.65/898.20
  6. Step 6: Final answer
    x = 689.88

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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.