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Finding the Fourth Proportional to 84.50, 126.52 and 78.81

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Solution

The fourth proportional to 84.50, 126.52 and 78.81 is: 117.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.50 : 126.52 = 78.81 : x
  2. Step 2: Convert to fraction form
    84.50/126.52 = 78.81/x
  3. Step 3: Cross multiply
    84.50x = 126.52 × 78.81
  4. Step 4: Simplify right side
    84.50x = 9,970.84
  5. Step 5: Solve for x
    x = 9,970.84/84.50
  6. Step 6: Final answer
    x = 117.99

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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.