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Finding the Fourth Proportional to 639.60, 883.15 and 499.48

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Solution

The fourth proportional to 639.60, 883.15 and 499.48 is: 689.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.60 : 883.15 = 499.48 : x
  2. Step 2: Convert to fraction form
    639.60/883.15 = 499.48/x
  3. Step 3: Cross multiply
    639.60x = 883.15 × 499.48
  4. Step 4: Simplify right side
    639.60x = 441,111.20
  5. Step 5: Solve for x
    x = 441,111.20/639.60
  6. Step 6: Final answer
    x = 689.66

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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.