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Finding the Fourth Proportional to 84.81, 127.25 and 39.18

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Solution

The fourth proportional to 84.81, 127.25 and 39.18 is: 58.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.81 : 127.25 = 39.18 : x
  2. Step 2: Convert to fraction form
    84.81/127.25 = 39.18/x
  3. Step 3: Cross multiply
    84.81x = 127.25 × 39.18
  4. Step 4: Simplify right side
    84.81x = 4,985.46
  5. Step 5: Solve for x
    x = 4,985.46/84.81
  6. Step 6: Final answer
    x = 58.78

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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.