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Finding the Fourth Proportional to 371.78, 557.19 and 280.21

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Solution

The fourth proportional to 371.78, 557.19 and 280.21 is: 419.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    371.78 : 557.19 = 280.21 : x
  2. Step 2: Convert to fraction form
    371.78/557.19 = 280.21/x
  3. Step 3: Cross multiply
    371.78x = 557.19 × 280.21
  4. Step 4: Simplify right side
    371.78x = 156,130.21
  5. Step 5: Solve for x
    x = 156,130.21/371.78
  6. Step 6: Final answer
    x = 419.95

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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.