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Finding the Fourth Proportional to 122.50, 169.05 and 70.78

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Solution

The fourth proportional to 122.50, 169.05 and 70.78 is: 97.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    122.50 : 169.05 = 70.78 : x
  2. Step 2: Convert to fraction form
    122.50/169.05 = 70.78/x
  3. Step 3: Cross multiply
    122.50x = 169.05 × 70.78
  4. Step 4: Simplify right side
    122.50x = 11,965.36
  5. Step 5: Solve for x
    x = 11,965.36/122.50
  6. Step 6: Final answer
    x = 97.68

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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.