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Finding the Fourth Proportional to 769.80, 1,153.79 and 423.30

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Solution

The fourth proportional to 769.80, 1,153.79 and 423.30 is: 634.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    769.80 : 1,153.79 = 423.30 : x
  2. Step 2: Convert to fraction form
    769.80/1,153.79 = 423.30/x
  3. Step 3: Cross multiply
    769.80x = 1,153.79 × 423.30
  4. Step 4: Simplify right side
    769.80x = 488,397.19
  5. Step 5: Solve for x
    x = 488,397.19/769.80
  6. Step 6: Final answer
    x = 634.45

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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.