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Finding the Fourth Proportional to 15.48, 21.30 and 13.65

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Solution

The fourth proportional to 15.48, 21.30 and 13.65 is: 18.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.48 : 21.30 = 13.65 : x
  2. Step 2: Convert to fraction form
    15.48/21.30 = 13.65/x
  3. Step 3: Cross multiply
    15.48x = 21.30 × 13.65
  4. Step 4: Simplify right side
    15.48x = 290.75
  5. Step 5: Solve for x
    x = 290.75/15.48
  6. Step 6: Final answer
    x = 18.78

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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.