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Finding the Fourth Proportional to 123.12, 170 and 76.56

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Solution

The fourth proportional to 123.12, 170 and 76.56 is: 105.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.12 : 170 = 76.56 : x
  2. Step 2: Convert to fraction form
    123.12/170 = 76.56/x
  3. Step 3: Cross multiply
    123.12x = 170 × 76.56
  4. Step 4: Simplify right side
    123.12x = 13,015.20
  5. Step 5: Solve for x
    x = 13,015.20/123.12
  6. Step 6: Final answer
    x = 105.71

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.