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Finding the Fourth Proportional to 647.91, 893.21 and 498.78

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Solution

The fourth proportional to 647.91, 893.21 and 498.78 is: 687.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.91 : 893.21 = 498.78 : x
  2. Step 2: Convert to fraction form
    647.91/893.21 = 498.78/x
  3. Step 3: Cross multiply
    647.91x = 893.21 × 498.78
  4. Step 4: Simplify right side
    647.91x = 445,512.79
  5. Step 5: Solve for x
    x = 445,512.79/647.91
  6. Step 6: Final answer
    x = 687.62

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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.