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Finding the Fourth Proportional to 647.12, 891.96 and 499.70

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Solution

The fourth proportional to 647.12, 891.96 and 499.70 is: 688.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.12 : 891.96 = 499.70 : x
  2. Step 2: Convert to fraction form
    647.12/891.96 = 499.70/x
  3. Step 3: Cross multiply
    647.12x = 891.96 × 499.70
  4. Step 4: Simplify right side
    647.12x = 445,712.41
  5. Step 5: Solve for x
    x = 445,712.41/647.12
  6. Step 6: Final answer
    x = 688.76

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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.