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Finding the Fourth Proportional to 72.77, 100.42 and 39.58

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Solution

The fourth proportional to 72.77, 100.42 and 39.58 is: 54.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.77 : 100.42 = 39.58 : x
  2. Step 2: Convert to fraction form
    72.77/100.42 = 39.58/x
  3. Step 3: Cross multiply
    72.77x = 100.42 × 39.58
  4. Step 4: Simplify right side
    72.77x = 3,974.35
  5. Step 5: Solve for x
    x = 3,974.35/72.77
  6. Step 6: Final answer
    x = 54.62

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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.