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Finding the Fourth Proportional to 19.31, 28.95 and 12.45

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Solution

The fourth proportional to 19.31, 28.95 and 12.45 is: 18.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    19.31 : 28.95 = 12.45 : x
  2. Step 2: Convert to fraction form
    19.31/28.95 = 12.45/x
  3. Step 3: Cross multiply
    19.31x = 28.95 × 12.45
  4. Step 4: Simplify right side
    19.31x = 360.49
  5. Step 5: Solve for x
    x = 360.49/19.31
  6. Step 6: Final answer
    x = 18.67

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.