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Finding the Fourth Proportional to 84.78, 116.79 and 72.54

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Solution

The fourth proportional to 84.78, 116.79 and 72.54 is: 99.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.78 : 116.79 = 72.54 : x
  2. Step 2: Convert to fraction form
    84.78/116.79 = 72.54/x
  3. Step 3: Cross multiply
    84.78x = 116.79 × 72.54
  4. Step 4: Simplify right side
    84.78x = 8,471.95
  5. Step 5: Solve for x
    x = 8,471.95/84.78
  6. Step 6: Final answer
    x = 99.93

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.