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Finding the Fourth Proportional to 372.34, 558.38 and 128.80

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Solution

The fourth proportional to 372.34, 558.38 and 128.80 is: 193.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    372.34 : 558.38 = 128.80 : x
  2. Step 2: Convert to fraction form
    372.34/558.38 = 128.80/x
  3. Step 3: Cross multiply
    372.34x = 558.38 × 128.80
  4. Step 4: Simplify right side
    372.34x = 71,919.34
  5. Step 5: Solve for x
    x = 71,919.34/372.34
  6. Step 6: Final answer
    x = 193.16

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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.