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Finding the Fourth Proportional to 372.21, 558.32 and 128.75

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Solution

The fourth proportional to 372.21, 558.32 and 128.75 is: 193.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    372.21 : 558.32 = 128.75 : x
  2. Step 2: Convert to fraction form
    372.21/558.32 = 128.75/x
  3. Step 3: Cross multiply
    372.21x = 558.32 × 128.75
  4. Step 4: Simplify right side
    372.21x = 71,880.26
  5. Step 5: Solve for x
    x = 71,880.26/372.21
  6. Step 6: Final answer
    x = 193.12

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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.