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Finding the Fourth Proportional to 498.78, 688.29 and 393.66

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Solution

The fourth proportional to 498.78, 688.29 and 393.66 is: 543.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.78 : 688.29 = 393.66 : x
  2. Step 2: Convert to fraction form
    498.78/688.29 = 393.66/x
  3. Step 3: Cross multiply
    498.78x = 688.29 × 393.66
  4. Step 4: Simplify right side
    498.78x = 270,952.24
  5. Step 5: Solve for x
    x = 270,952.24/498.78
  6. Step 6: Final answer
    x = 543.23

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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.