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Finding the Fourth Proportional to 372.40, 558.23 and 128.79

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Solution

The fourth proportional to 372.40, 558.23 and 128.79 is: 193.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    372.40 : 558.23 = 128.79 : x
  2. Step 2: Convert to fraction form
    372.40/558.23 = 128.79/x
  3. Step 3: Cross multiply
    372.40x = 558.23 × 128.79
  4. Step 4: Simplify right side
    372.40x = 71,893.80
  5. Step 5: Solve for x
    x = 71,893.80/372.40
  6. Step 6: Final answer
    x = 193.06

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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.