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Finding the Fourth Proportional to 52.25, 78.38 and 20.21

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Solution

The fourth proportional to 52.25, 78.38 and 20.21 is: 30.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    52.25 : 78.38 = 20.21 : x
  2. Step 2: Convert to fraction form
    52.25/78.38 = 20.21/x
  3. Step 3: Cross multiply
    52.25x = 78.38 × 20.21
  4. Step 4: Simplify right side
    52.25x = 1,583.96
  5. Step 5: Solve for x
    x = 1,583.96/52.25
  6. Step 6: Final answer
    x = 30.32

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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.