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Finding the Fourth Proportional to 12.80, 16.90 and 12.80

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Solution

The fourth proportional to 12.80, 16.90 and 12.80 is: 16.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.80 : 16.90 = 12.80 : x
  2. Step 2: Convert to fraction form
    12.80/16.90 = 12.80/x
  3. Step 3: Cross multiply
    12.80x = 16.90 × 12.80
  4. Step 4: Simplify right side
    12.80x = 216.32
  5. Step 5: Solve for x
    x = 216.32/12.80
  6. Step 6: Final answer
    x = 16.90

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Why These Related Problems?

These problems maintain the same ratio (1.32) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.