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Finding the Fourth Proportional to 559.78, 840.08 and 478.78

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Solution

The fourth proportional to 559.78, 840.08 and 478.78 is: 718.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    559.78 : 840.08 = 478.78 : x
  2. Step 2: Convert to fraction form
    559.78/840.08 = 478.78/x
  3. Step 3: Cross multiply
    559.78x = 840.08 × 478.78
  4. Step 4: Simplify right side
    559.78x = 402,213.50
  5. Step 5: Solve for x
    x = 402,213.50/559.78
  6. Step 6: Final answer
    x = 718.52

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.