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Finding the Fourth Proportional to 372.30, 558.39 and 128.79

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Solution

The fourth proportional to 372.30, 558.39 and 128.79 is: 193.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    372.30 : 558.39 = 128.79 : x
  2. Step 2: Convert to fraction form
    372.30/558.39 = 128.79/x
  3. Step 3: Cross multiply
    372.30x = 558.39 × 128.79
  4. Step 4: Simplify right side
    372.30x = 71,915.53
  5. Step 5: Solve for x
    x = 71,915.53/372.30
  6. Step 6: Final answer
    x = 193.17

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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.