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Finding the Fourth Proportional to 61.81, 92.72 and 21.24

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Solution

The fourth proportional to 61.81, 92.72 and 21.24 is: 31.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.81 : 92.72 = 21.24 : x
  2. Step 2: Convert to fraction form
    61.81/92.72 = 21.24/x
  3. Step 3: Cross multiply
    61.81x = 92.72 × 21.24
  4. Step 4: Simplify right side
    61.81x = 1,969.43
  5. Step 5: Solve for x
    x = 1,969.43/61.81
  6. Step 6: Final answer
    x = 31.86

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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.