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Finding the Fourth Proportional to 688.23, 949.79 and 393.55

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Solution

The fourth proportional to 688.23, 949.79 and 393.55 is: 543.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.23 : 949.79 = 393.55 : x
  2. Step 2: Convert to fraction form
    688.23/949.79 = 393.55/x
  3. Step 3: Cross multiply
    688.23x = 949.79 × 393.55
  4. Step 4: Simplify right side
    688.23x = 373,789.85
  5. Step 5: Solve for x
    x = 373,789.85/688.23
  6. Step 6: Final answer
    x = 543.12

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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.