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Finding the Fourth Proportional to 559.40, 839.10 and 478.40

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Solution

The fourth proportional to 559.40, 839.10 and 478.40 is: 717.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    559.40 : 839.10 = 478.40 : x
  2. Step 2: Convert to fraction form
    559.40/839.10 = 478.40/x
  3. Step 3: Cross multiply
    559.40x = 839.10 × 478.40
  4. Step 4: Simplify right side
    559.40x = 401,425.44
  5. Step 5: Solve for x
    x = 401,425.44/559.40
  6. Step 6: Final answer
    x = 717.60

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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.