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Finding the Fourth Proportional to 84.95, 127.96 and 80.40

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Solution

The fourth proportional to 84.95, 127.96 and 80.40 is: 121.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.95 : 127.96 = 80.40 : x
  2. Step 2: Convert to fraction form
    84.95/127.96 = 80.40/x
  3. Step 3: Cross multiply
    84.95x = 127.96 × 80.40
  4. Step 4: Simplify right side
    84.95x = 10,287.98
  5. Step 5: Solve for x
    x = 10,287.98/84.95
  6. Step 6: Final answer
    x = 121.11

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.