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Finding the Fourth Proportional to 84.60, 117.36 and 77.40

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Solution

The fourth proportional to 84.60, 117.36 and 77.40 is: 107.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.60 : 117.36 = 77.40 : x
  2. Step 2: Convert to fraction form
    84.60/117.36 = 77.40/x
  3. Step 3: Cross multiply
    84.60x = 117.36 × 77.40
  4. Step 4: Simplify right side
    84.60x = 9,083.66
  5. Step 5: Solve for x
    x = 9,083.66/84.60
  6. Step 6: Final answer
    x = 107.37

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.