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Finding the Fourth Proportional to 122.58, 169.16 and 72.79

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Solution

The fourth proportional to 122.58, 169.16 and 72.79 is: 100.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    122.58 : 169.16 = 72.79 : x
  2. Step 2: Convert to fraction form
    122.58/169.16 = 72.79/x
  3. Step 3: Cross multiply
    122.58x = 169.16 × 72.79
  4. Step 4: Simplify right side
    122.58x = 12,312.79
  5. Step 5: Solve for x
    x = 12,312.79/122.58
  6. Step 6: Final answer
    x = 100.45

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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.