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Finding the Fourth Proportional to 663.90, 915.21 and 498.12

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Solution

The fourth proportional to 663.90, 915.21 and 498.12 is: 686.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.90 : 915.21 = 498.12 : x
  2. Step 2: Convert to fraction form
    663.90/915.21 = 498.12/x
  3. Step 3: Cross multiply
    663.90x = 915.21 × 498.12
  4. Step 4: Simplify right side
    663.90x = 455,884.41
  5. Step 5: Solve for x
    x = 455,884.41/663.90
  6. Step 6: Final answer
    x = 686.68

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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.