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Finding the Fourth Proportional to 688.47, 949.64 and 492.09

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Solution

The fourth proportional to 688.47, 949.64 and 492.09 is: 678.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.47 : 949.64 = 492.09 : x
  2. Step 2: Convert to fraction form
    688.47/949.64 = 492.09/x
  3. Step 3: Cross multiply
    688.47x = 949.64 × 492.09
  4. Step 4: Simplify right side
    688.47x = 467,305.89
  5. Step 5: Solve for x
    x = 467,305.89/688.47
  6. Step 6: Final answer
    x = 678.76

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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.