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Finding the Fourth Proportional to 12.57, 18.86 and 5.45

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Solution

The fourth proportional to 12.57, 18.86 and 5.45 is: 8.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.57 : 18.86 = 5.45 : x
  2. Step 2: Convert to fraction form
    12.57/18.86 = 5.45/x
  3. Step 3: Cross multiply
    12.57x = 18.86 × 5.45
  4. Step 4: Simplify right side
    12.57x = 102.67
  5. Step 5: Solve for x
    x = 102.67/12.57
  6. Step 6: Final answer
    x = 8.17

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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.