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Finding the Fourth Proportional to 47.88, 71.40 and 40.20

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Solution

The fourth proportional to 47.88, 71.40 and 40.20 is: 59.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.88 : 71.40 = 40.20 : x
  2. Step 2: Convert to fraction form
    47.88/71.40 = 40.20/x
  3. Step 3: Cross multiply
    47.88x = 71.40 × 40.20
  4. Step 4: Simplify right side
    47.88x = 2,870.28
  5. Step 5: Solve for x
    x = 2,870.28/47.88
  6. Step 6: Final answer
    x = 59.95

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.