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Finding the Fourth Proportional to 498.78, 688.23 and 288.99

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Solution

The fourth proportional to 498.78, 688.23 and 288.99 is: 398.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.78 : 688.23 = 288.99 : x
  2. Step 2: Convert to fraction form
    498.78/688.23 = 288.99/x
  3. Step 3: Cross multiply
    498.78x = 688.23 × 288.99
  4. Step 4: Simplify right side
    498.78x = 198,891.59
  5. Step 5: Solve for x
    x = 198,891.59/498.78
  6. Step 6: Final answer
    x = 398.76

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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.