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Finding the Fourth Proportional to 688.32, 949.87 and 393.55

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Solution

The fourth proportional to 688.32, 949.87 and 393.55 is: 543.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.32 : 949.87 = 393.55 : x
  2. Step 2: Convert to fraction form
    688.32/949.87 = 393.55/x
  3. Step 3: Cross multiply
    688.32x = 949.87 × 393.55
  4. Step 4: Simplify right side
    688.32x = 373,821.34
  5. Step 5: Solve for x
    x = 373,821.34/688.32
  6. Step 6: Final answer
    x = 543.09

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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.