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Finding the Fourth Proportional to 13.75, 20.57 and 7.70

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Solution

The fourth proportional to 13.75, 20.57 and 7.70 is: 11.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.75 : 20.57 = 7.70 : x
  2. Step 2: Convert to fraction form
    13.75/20.57 = 7.70/x
  3. Step 3: Cross multiply
    13.75x = 20.57 × 7.70
  4. Step 4: Simplify right side
    13.75x = 158.40
  5. Step 5: Solve for x
    x = 158.40/13.75
  6. Step 6: Final answer
    x = 11.52

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.