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Finding the Fourth Proportional to 52.21, 78.28 and 20.11

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Solution

The fourth proportional to 52.21, 78.28 and 20.11 is: 30.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    52.21 : 78.28 = 20.11 : x
  2. Step 2: Convert to fraction form
    52.21/78.28 = 20.11/x
  3. Step 3: Cross multiply
    52.21x = 78.28 × 20.11
  4. Step 4: Simplify right side
    52.21x = 1,574.21
  5. Step 5: Solve for x
    x = 1,574.21/52.21
  6. Step 6: Final answer
    x = 30.15

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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.