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Finding the Fourth Proportional to 688.28, 949.68 and 393.47

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Solution

The fourth proportional to 688.28, 949.68 and 393.47 is: 542.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.28 : 949.68 = 393.47 : x
  2. Step 2: Convert to fraction form
    688.28/949.68 = 393.47/x
  3. Step 3: Cross multiply
    688.28x = 949.68 × 393.47
  4. Step 4: Simplify right side
    688.28x = 373,670.59
  5. Step 5: Solve for x
    x = 373,670.59/688.28
  6. Step 6: Final answer
    x = 542.90

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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.