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Finding the Fourth Proportional to 72.66, 108.78 and 61.12

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Solution

The fourth proportional to 72.66, 108.78 and 61.12 is: 91.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.66 : 108.78 = 61.12 : x
  2. Step 2: Convert to fraction form
    72.66/108.78 = 61.12/x
  3. Step 3: Cross multiply
    72.66x = 108.78 × 61.12
  4. Step 4: Simplify right side
    72.66x = 6,648.63
  5. Step 5: Solve for x
    x = 6,648.63/72.66
  6. Step 6: Final answer
    x = 91.50

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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.