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Finding the Fourth Proportional to 13.99, 20.91 and 10.78

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Solution

The fourth proportional to 13.99, 20.91 and 10.78 is: 16.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.99 : 20.91 = 10.78 : x
  2. Step 2: Convert to fraction form
    13.99/20.91 = 10.78/x
  3. Step 3: Cross multiply
    13.99x = 20.91 × 10.78
  4. Step 4: Simplify right side
    13.99x = 225.41
  5. Step 5: Solve for x
    x = 225.41/13.99
  6. Step 6: Final answer
    x = 16.11

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.