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Finding the Fourth Proportional to 748.28, 1,122.21 and 285.74

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Solution

The fourth proportional to 748.28, 1,122.21 and 285.74 is: 428.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    748.28 : 1,122.21 = 285.74 : x
  2. Step 2: Convert to fraction form
    748.28/1,122.21 = 285.74/x
  3. Step 3: Cross multiply
    748.28x = 1,122.21 × 285.74
  4. Step 4: Simplify right side
    748.28x = 320,660.29
  5. Step 5: Solve for x
    x = 320,660.29/748.28
  6. Step 6: Final answer
    x = 428.53

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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.