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Finding the Fourth Proportional to 122.80, 169.41 and 78.52

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Solution

The fourth proportional to 122.80, 169.41 and 78.52 is: 108.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    122.80 : 169.41 = 78.52 : x
  2. Step 2: Convert to fraction form
    122.80/169.41 = 78.52/x
  3. Step 3: Cross multiply
    122.80x = 169.41 × 78.52
  4. Step 4: Simplify right side
    122.80x = 13,302.07
  5. Step 5: Solve for x
    x = 13,302.07/122.80
  6. Step 6: Final answer
    x = 108.32

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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.