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Finding the Fourth Proportional to 12.90, 17.65 and 12.88

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Solution

The fourth proportional to 12.90, 17.65 and 12.88 is: 17.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.90 : 17.65 = 12.88 : x
  2. Step 2: Convert to fraction form
    12.90/17.65 = 12.88/x
  3. Step 3: Cross multiply
    12.90x = 17.65 × 12.88
  4. Step 4: Simplify right side
    12.90x = 227.33
  5. Step 5: Solve for x
    x = 227.33/12.90
  6. Step 6: Final answer
    x = 17.62

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.