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Finding the Fourth Proportional to 12.87, 19.30 and 4.86

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Solution

The fourth proportional to 12.87, 19.30 and 4.86 is: 7.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.87 : 19.30 = 4.86 : x
  2. Step 2: Convert to fraction form
    12.87/19.30 = 4.86/x
  3. Step 3: Cross multiply
    12.87x = 19.30 × 4.86
  4. Step 4: Simplify right side
    12.87x = 93.71
  5. Step 5: Solve for x
    x = 93.71/12.87
  6. Step 6: Final answer
    x = 7.28

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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.