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Finding the Fourth Proportional to 125.21, 172.79 and 72.76

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Solution

The fourth proportional to 125.21, 172.79 and 72.76 is: 100.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    125.21 : 172.79 = 72.76 : x
  2. Step 2: Convert to fraction form
    125.21/172.79 = 72.76/x
  3. Step 3: Cross multiply
    125.21x = 172.79 × 72.76
  4. Step 4: Simplify right side
    125.21x = 12,573.06
  5. Step 5: Solve for x
    x = 12,573.06/125.21
  6. Step 6: Final answer
    x = 100.42

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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.