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Finding the Fourth Proportional to 82.36, 123.57 and 78.91

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Solution

The fourth proportional to 82.36, 123.57 and 78.91 is: 118.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.36 : 123.57 = 78.91 : x
  2. Step 2: Convert to fraction form
    82.36/123.57 = 78.91/x
  3. Step 3: Cross multiply
    82.36x = 123.57 × 78.91
  4. Step 4: Simplify right side
    82.36x = 9,750.91
  5. Step 5: Solve for x
    x = 9,750.91/82.36
  6. Step 6: Final answer
    x = 118.39

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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.