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Finding the Fourth Proportional to 31.48, 47.28 and 31.20

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Solution

The fourth proportional to 31.48, 47.28 and 31.20 is: 46.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.48 : 47.28 = 31.20 : x
  2. Step 2: Convert to fraction form
    31.48/47.28 = 31.20/x
  3. Step 3: Cross multiply
    31.48x = 47.28 × 31.20
  4. Step 4: Simplify right side
    31.48x = 1,475.14
  5. Step 5: Solve for x
    x = 1,475.14/31.48
  6. Step 6: Final answer
    x = 46.86

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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.