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Finding the Fourth Proportional to 688.45, 949.81 and 393.55

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Solution

The fourth proportional to 688.45, 949.81 and 393.55 is: 542.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.45 : 949.81 = 393.55 : x
  2. Step 2: Convert to fraction form
    688.45/949.81 = 393.55/x
  3. Step 3: Cross multiply
    688.45x = 949.81 × 393.55
  4. Step 4: Simplify right side
    688.45x = 373,797.73
  5. Step 5: Solve for x
    x = 373,797.73/688.45
  6. Step 6: Final answer
    x = 542.96

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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.