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Finding the Fourth Proportional to 688.20, 949.74 and 393.55

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Solution

The fourth proportional to 688.20, 949.74 and 393.55 is: 543.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.20 : 949.74 = 393.55 : x
  2. Step 2: Convert to fraction form
    688.20/949.74 = 393.55/x
  3. Step 3: Cross multiply
    688.20x = 949.74 × 393.55
  4. Step 4: Simplify right side
    688.20x = 373,770.18
  5. Step 5: Solve for x
    x = 373,770.18/688.20
  6. Step 6: Final answer
    x = 543.11

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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.