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Finding the Fourth Proportional to 911.43, 1,368 and 478.89

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Solution

The fourth proportional to 911.43, 1,368 and 478.89 is: 718.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    911.43 : 1,368 = 478.89 : x
  2. Step 2: Convert to fraction form
    911.43/1,368 = 478.89/x
  3. Step 3: Cross multiply
    911.43x = 1,368 × 478.89
  4. Step 4: Simplify right side
    911.43x = 655,121.52
  5. Step 5: Solve for x
    x = 655,121.52/911.43
  6. Step 6: Final answer
    x = 718.78

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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.