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Finding the Fourth Proportional to 819.12, 1,129.76 and 653.12

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Solution

The fourth proportional to 819.12, 1,129.76 and 653.12 is: 900.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.12 : 1,129.76 = 653.12 : x
  2. Step 2: Convert to fraction form
    819.12/1,129.76 = 653.12/x
  3. Step 3: Cross multiply
    819.12x = 1,129.76 × 653.12
  4. Step 4: Simplify right side
    819.12x = 737,868.85
  5. Step 5: Solve for x
    x = 737,868.85/819.12
  6. Step 6: Final answer
    x = 900.81

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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.