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Finding the Fourth Proportional to 15.30, 21.07 and 12.99

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Solution

The fourth proportional to 15.30, 21.07 and 12.99 is: 17.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.30 : 21.07 = 12.99 : x
  2. Step 2: Convert to fraction form
    15.30/21.07 = 12.99/x
  3. Step 3: Cross multiply
    15.30x = 21.07 × 12.99
  4. Step 4: Simplify right side
    15.30x = 273.70
  5. Step 5: Solve for x
    x = 273.70/15.30
  6. Step 6: Final answer
    x = 17.89

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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.