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Finding the Fourth Proportional to 72.92, 108.61 and 72.78

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Solution

The fourth proportional to 72.92, 108.61 and 72.78 is: 108.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.92 : 108.61 = 72.78 : x
  2. Step 2: Convert to fraction form
    72.92/108.61 = 72.78/x
  3. Step 3: Cross multiply
    72.92x = 108.61 × 72.78
  4. Step 4: Simplify right side
    72.92x = 7,904.64
  5. Step 5: Solve for x
    x = 7,904.64/72.92
  6. Step 6: Final answer
    x = 108.40

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.