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Finding the Fourth Proportional to 15.20, 21 and 13.76

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Solution

The fourth proportional to 15.20, 21 and 13.76 is: 19.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.20 : 21 = 13.76 : x
  2. Step 2: Convert to fraction form
    15.20/21 = 13.76/x
  3. Step 3: Cross multiply
    15.20x = 21 × 13.76
  4. Step 4: Simplify right side
    15.20x = 288.96
  5. Step 5: Solve for x
    x = 288.96/15.20
  6. Step 6: Final answer
    x = 19.01

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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.