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Finding the Fourth Proportional to 29.70, 40.98 and 18.78

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Solution

The fourth proportional to 29.70, 40.98 and 18.78 is: 25.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    29.70 : 40.98 = 18.78 : x
  2. Step 2: Convert to fraction form
    29.70/40.98 = 18.78/x
  3. Step 3: Cross multiply
    29.70x = 40.98 × 18.78
  4. Step 4: Simplify right side
    29.70x = 769.60
  5. Step 5: Solve for x
    x = 769.60/29.70
  6. Step 6: Final answer
    x = 25.91

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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.