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Finding the Fourth Proportional to 772.60, 1,158.72 and 285.70

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Solution

The fourth proportional to 772.60, 1,158.72 and 285.70 is: 428.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    772.60 : 1,158.72 = 285.70 : x
  2. Step 2: Convert to fraction form
    772.60/1,158.72 = 285.70/x
  3. Step 3: Cross multiply
    772.60x = 1,158.72 × 285.70
  4. Step 4: Simplify right side
    772.60x = 331,046.30
  5. Step 5: Solve for x
    x = 331,046.30/772.60
  6. Step 6: Final answer
    x = 428.48

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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.