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Finding the Fourth Proportional to 72.41, 108.62 and 21.05

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Solution

The fourth proportional to 72.41, 108.62 and 21.05 is: 31.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.41 : 108.62 = 21.05 : x
  2. Step 2: Convert to fraction form
    72.41/108.62 = 21.05/x
  3. Step 3: Cross multiply
    72.41x = 108.62 × 21.05
  4. Step 4: Simplify right side
    72.41x = 2,285.96
  5. Step 5: Solve for x
    x = 2,285.96/72.41
  6. Step 6: Final answer
    x = 31.57

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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.