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Finding the Fourth Proportional to 47.70, 71.55 and 40.80

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Solution

The fourth proportional to 47.70, 71.55 and 40.80 is: 61.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.70 : 71.55 = 40.80 : x
  2. Step 2: Convert to fraction form
    47.70/71.55 = 40.80/x
  3. Step 3: Cross multiply
    47.70x = 71.55 × 40.80
  4. Step 4: Simplify right side
    47.70x = 2,919.24
  5. Step 5: Solve for x
    x = 2,919.24/47.70
  6. Step 6: Final answer
    x = 61.20

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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.