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Finding the Fourth Proportional to 47.49, 71.19 and 20.40

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Solution

The fourth proportional to 47.49, 71.19 and 20.40 is: 30.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.49 : 71.19 = 20.40 : x
  2. Step 2: Convert to fraction form
    47.49/71.19 = 20.40/x
  3. Step 3: Cross multiply
    47.49x = 71.19 × 20.40
  4. Step 4: Simplify right side
    47.49x = 1,452.28
  5. Step 5: Solve for x
    x = 1,452.28/47.49
  6. Step 6: Final answer
    x = 30.58

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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.