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Finding the Fourth Proportional to 47.22, 70.80 and 31.20

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Solution

The fourth proportional to 47.22, 70.80 and 31.20 is: 46.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.22 : 70.80 = 31.20 : x
  2. Step 2: Convert to fraction form
    47.22/70.80 = 31.20/x
  3. Step 3: Cross multiply
    47.22x = 70.80 × 31.20
  4. Step 4: Simplify right side
    47.22x = 2,208.96
  5. Step 5: Solve for x
    x = 2,208.96/47.22
  6. Step 6: Final answer
    x = 46.78

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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.