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Finding the Fourth Proportional to 663.91, 915.69 and 486.79

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Solution

The fourth proportional to 663.91, 915.69 and 486.79 is: 671.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.91 : 915.69 = 486.79 : x
  2. Step 2: Convert to fraction form
    663.91/915.69 = 486.79/x
  3. Step 3: Cross multiply
    663.91x = 915.69 × 486.79
  4. Step 4: Simplify right side
    663.91x = 445,750.68
  5. Step 5: Solve for x
    x = 445,750.68/663.91
  6. Step 6: Final answer
    x = 671.40

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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.