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Finding the Fourth Proportional to 688.18, 949.70 and 393.45

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Solution

The fourth proportional to 688.18, 949.70 and 393.45 is: 542.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.18 : 949.70 = 393.45 : x
  2. Step 2: Convert to fraction form
    688.18/949.70 = 393.45/x
  3. Step 3: Cross multiply
    688.18x = 949.70 × 393.45
  4. Step 4: Simplify right side
    688.18x = 373,659.47
  5. Step 5: Solve for x
    x = 373,659.47/688.18
  6. Step 6: Final answer
    x = 542.97

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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.