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Finding the Fourth Proportional to 819.70, 1,131.30 and 470.38

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Solution

The fourth proportional to 819.70, 1,131.30 and 470.38 is: 649.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.70 : 1,131.30 = 470.38 : x
  2. Step 2: Convert to fraction form
    819.70/1,131.30 = 470.38/x
  3. Step 3: Cross multiply
    819.70x = 1,131.30 × 470.38
  4. Step 4: Simplify right side
    819.70x = 532,140.89
  5. Step 5: Solve for x
    x = 532,140.89/819.70
  6. Step 6: Final answer
    x = 649.19

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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.