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Finding the Fourth Proportional to 13.58, 18.76 and 9.90

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Solution

The fourth proportional to 13.58, 18.76 and 9.90 is: 13.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.58 : 18.76 = 9.90 : x
  2. Step 2: Convert to fraction form
    13.58/18.76 = 9.90/x
  3. Step 3: Cross multiply
    13.58x = 18.76 × 9.90
  4. Step 4: Simplify right side
    13.58x = 185.72
  5. Step 5: Solve for x
    x = 185.72/13.58
  6. Step 6: Final answer
    x = 13.68

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.