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Finding the Fourth Proportional to 47.50, 71.18 and 21.80

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Solution

The fourth proportional to 47.50, 71.18 and 21.80 is: 32.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.50 : 71.18 = 21.80 : x
  2. Step 2: Convert to fraction form
    47.50/71.18 = 21.80/x
  3. Step 3: Cross multiply
    47.50x = 71.18 × 21.80
  4. Step 4: Simplify right side
    47.50x = 1,551.69
  5. Step 5: Solve for x
    x = 1,551.69/47.50
  6. Step 6: Final answer
    x = 32.67

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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.