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Finding the Fourth Proportional to 84.66, 126.26 and 78.89

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Solution

The fourth proportional to 84.66, 126.26 and 78.89 is: 117.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.66 : 126.26 = 78.89 : x
  2. Step 2: Convert to fraction form
    84.66/126.26 = 78.89/x
  3. Step 3: Cross multiply
    84.66x = 126.26 × 78.89
  4. Step 4: Simplify right side
    84.66x = 9,959.92
  5. Step 5: Solve for x
    x = 9,959.92/84.66
  6. Step 6: Final answer
    x = 117.65

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.