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Finding the Fourth Proportional to 78.94, 118.54 and 72.61

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Solution

The fourth proportional to 78.94, 118.54 and 72.61 is: 109.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.94 : 118.54 = 72.61 : x
  2. Step 2: Convert to fraction form
    78.94/118.54 = 72.61/x
  3. Step 3: Cross multiply
    78.94x = 118.54 × 72.61
  4. Step 4: Simplify right side
    78.94x = 8,606.60
  5. Step 5: Solve for x
    x = 8,606.60/78.94
  6. Step 6: Final answer
    x = 109.03

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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.