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Finding the Fourth Proportional to 630.20, 869.45 and 393.98

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Solution

The fourth proportional to 630.20, 869.45 and 393.98 is: 543.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    630.20 : 869.45 = 393.98 : x
  2. Step 2: Convert to fraction form
    630.20/869.45 = 393.98/x
  3. Step 3: Cross multiply
    630.20x = 869.45 × 393.98
  4. Step 4: Simplify right side
    630.20x = 342,539.59
  5. Step 5: Solve for x
    x = 342,539.59/630.20
  6. Step 6: Final answer
    x = 543.55

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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.