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Finding the Fourth Proportional to 81.50, 122.37 and 78.59

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Solution

The fourth proportional to 81.50, 122.37 and 78.59 is: 118.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.50 : 122.37 = 78.59 : x
  2. Step 2: Convert to fraction form
    81.50/122.37 = 78.59/x
  3. Step 3: Cross multiply
    81.50x = 122.37 × 78.59
  4. Step 4: Simplify right side
    81.50x = 9,617.06
  5. Step 5: Solve for x
    x = 9,617.06/81.50
  6. Step 6: Final answer
    x = 118.00

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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.