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Finding the Fourth Proportional to 82.12, 122.35 and 78.04

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Solution

The fourth proportional to 82.12, 122.35 and 78.04 is: 116.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.12 : 122.35 = 78.04 : x
  2. Step 2: Convert to fraction form
    82.12/122.35 = 78.04/x
  3. Step 3: Cross multiply
    82.12x = 122.35 × 78.04
  4. Step 4: Simplify right side
    82.12x = 9,548.19
  5. Step 5: Solve for x
    x = 9,548.19/82.12
  6. Step 6: Final answer
    x = 116.27

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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.