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Finding the Fourth Proportional to 20, 30 and 15.56

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Solution

The fourth proportional to 20, 30 and 15.56 is: 23.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    20 : 30 = 15.56 : x
  2. Step 2: Convert to fraction form
    20/30 = 15.56/x
  3. Step 3: Cross multiply
    20x = 30 × 15.56
  4. Step 4: Simplify right side
    20x = 466.80
  5. Step 5: Solve for x
    x = 466.80/20
  6. Step 6: Final answer
    x = 23.34

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Double scale
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1.5x scale

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.