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Finding the Fourth Proportional to 84.98, 128.03 and 77.17

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Solution

The fourth proportional to 84.98, 128.03 and 77.17 is: 116.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.98 : 128.03 = 77.17 : x
  2. Step 2: Convert to fraction form
    84.98/128.03 = 77.17/x
  3. Step 3: Cross multiply
    84.98x = 128.03 × 77.17
  4. Step 4: Simplify right side
    84.98x = 9,880.08
  5. Step 5: Solve for x
    x = 9,880.08/84.98
  6. Step 6: Final answer
    x = 116.26

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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.