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Finding the Fourth Proportional to 748.15, 1,121.38 and 285.64

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Solution

The fourth proportional to 748.15, 1,121.38 and 285.64 is: 428.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    748.15 : 1,121.38 = 285.64 : x
  2. Step 2: Convert to fraction form
    748.15/1,121.38 = 285.64/x
  3. Step 3: Cross multiply
    748.15x = 1,121.38 × 285.64
  4. Step 4: Simplify right side
    748.15x = 320,310.98
  5. Step 5: Solve for x
    x = 320,310.98/748.15
  6. Step 6: Final answer
    x = 428.14

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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.