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Finding the Fourth Proportional to 82.53, 123.78 and 39.20

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Solution

The fourth proportional to 82.53, 123.78 and 39.20 is: 58.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.53 : 123.78 = 39.20 : x
  2. Step 2: Convert to fraction form
    82.53/123.78 = 39.20/x
  3. Step 3: Cross multiply
    82.53x = 123.78 × 39.20
  4. Step 4: Simplify right side
    82.53x = 4,851.56
  5. Step 5: Solve for x
    x = 4,851.56/82.53
  6. Step 6: Final answer
    x = 58.79

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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.