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Finding the Fourth Proportional to 125.18, 172.65 and 81.47

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Solution

The fourth proportional to 125.18, 172.65 and 81.47 is: 112.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    125.18 : 172.65 = 81.47 : x
  2. Step 2: Convert to fraction form
    125.18/172.65 = 81.47/x
  3. Step 3: Cross multiply
    125.18x = 172.65 × 81.47
  4. Step 4: Simplify right side
    125.18x = 14,064.93
  5. Step 5: Solve for x
    x = 14,064.93/125.18
  6. Step 6: Final answer
    x = 112.36

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.