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Finding the Fourth Proportional to 12.70, 19.05 and 8.70

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Solution

The fourth proportional to 12.70, 19.05 and 8.70 is: 13.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.70 : 19.05 = 8.70 : x
  2. Step 2: Convert to fraction form
    12.70/19.05 = 8.70/x
  3. Step 3: Cross multiply
    12.70x = 19.05 × 8.70
  4. Step 4: Simplify right side
    12.70x = 165.74
  5. Step 5: Solve for x
    x = 165.74/12.70
  6. Step 6: Final answer
    x = 13.05

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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.