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Finding the Fourth Proportional to 769.78, 1,062.29 and 438.20

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Solution

The fourth proportional to 769.78, 1,062.29 and 438.20 is: 604.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    769.78 : 1,062.29 = 438.20 : x
  2. Step 2: Convert to fraction form
    769.78/1,062.29 = 438.20/x
  3. Step 3: Cross multiply
    769.78x = 1,062.29 × 438.20
  4. Step 4: Simplify right side
    769.78x = 465,492.52
  5. Step 5: Solve for x
    x = 465,492.52/769.78
  6. Step 6: Final answer
    x = 604.71

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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.