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Finding the Fourth Proportional to 630.78, 870.42 and 354.78

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Solution

The fourth proportional to 630.78, 870.42 and 354.78 is: 489.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    630.78 : 870.42 = 354.78 : x
  2. Step 2: Convert to fraction form
    630.78/870.42 = 354.78/x
  3. Step 3: Cross multiply
    630.78x = 870.42 × 354.78
  4. Step 4: Simplify right side
    630.78x = 308,807.61
  5. Step 5: Solve for x
    x = 308,807.61/630.78
  6. Step 6: Final answer
    x = 489.56

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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.