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Finding the Fourth Proportional to 748, 1,121.60 and 285.76

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Solution

The fourth proportional to 748, 1,121.60 and 285.76 is: 428.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    748 : 1,121.60 = 285.76 : x
  2. Step 2: Convert to fraction form
    748/1,121.60 = 285.76/x
  3. Step 3: Cross multiply
    748x = 1,121.60 × 285.76
  4. Step 4: Simplify right side
    748x = 320,508.42
  5. Step 5: Solve for x
    x = 320,508.42/748
  6. Step 6: Final answer
    x = 428.49

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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.