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Finding the Fourth Proportional to 20.53, 28.40 and 18.35

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Solution

The fourth proportional to 20.53, 28.40 and 18.35 is: 25.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.53 : 28.40 = 18.35 : x
  2. Step 2: Convert to fraction form
    20.53/28.40 = 18.35/x
  3. Step 3: Cross multiply
    20.53x = 28.40 × 18.35
  4. Step 4: Simplify right side
    20.53x = 521.20
  5. Step 5: Solve for x
    x = 521.20/20.53
  6. Step 6: Final answer
    x = 25.39

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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.