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Finding the Fourth Proportional to 47.90, 72.14 and 45.20

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Solution

The fourth proportional to 47.90, 72.14 and 45.20 is: 68.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.90 : 72.14 = 45.20 : x
  2. Step 2: Convert to fraction form
    47.90/72.14 = 45.20/x
  3. Step 3: Cross multiply
    47.90x = 72.14 × 45.20
  4. Step 4: Simplify right side
    47.90x = 3,260.73
  5. Step 5: Solve for x
    x = 3,260.73/47.90
  6. Step 6: Final answer
    x = 68.07

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.