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Finding the Fourth Proportional to 639.48, 881.80 and 499.35

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Solution

The fourth proportional to 639.48, 881.80 and 499.35 is: 688.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.48 : 881.80 = 499.35 : x
  2. Step 2: Convert to fraction form
    639.48/881.80 = 499.35/x
  3. Step 3: Cross multiply
    639.48x = 881.80 × 499.35
  4. Step 4: Simplify right side
    639.48x = 440,326.83
  5. Step 5: Solve for x
    x = 440,326.83/639.48
  6. Step 6: Final answer
    x = 688.57

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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.