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Finding the Fourth Proportional to 13.31, 19.93 and 7.90

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Solution

The fourth proportional to 13.31, 19.93 and 7.90 is: 11.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.31 : 19.93 = 7.90 : x
  2. Step 2: Convert to fraction form
    13.31/19.93 = 7.90/x
  3. Step 3: Cross multiply
    13.31x = 19.93 × 7.90
  4. Step 4: Simplify right side
    13.31x = 157.35
  5. Step 5: Solve for x
    x = 157.35/13.31
  6. Step 6: Final answer
    x = 11.82

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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.