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Finding the Fourth Proportional to 47.28, 70.72 and 31.20

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Solution

The fourth proportional to 47.28, 70.72 and 31.20 is: 46.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.28 : 70.72 = 31.20 : x
  2. Step 2: Convert to fraction form
    47.28/70.72 = 31.20/x
  3. Step 3: Cross multiply
    47.28x = 70.72 × 31.20
  4. Step 4: Simplify right side
    47.28x = 2,206.46
  5. Step 5: Solve for x
    x = 2,206.46/47.28
  6. Step 6: Final answer
    x = 46.67

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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.