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Finding the Fourth Proportional to 86.07, 118.74 and 56.91

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Solution

The fourth proportional to 86.07, 118.74 and 56.91 is: 78.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.07 : 118.74 = 56.91 : x
  2. Step 2: Convert to fraction form
    86.07/118.74 = 56.91/x
  3. Step 3: Cross multiply
    86.07x = 118.74 × 56.91
  4. Step 4: Simplify right side
    86.07x = 6,757.49
  5. Step 5: Solve for x
    x = 6,757.49/86.07
  6. Step 6: Final answer
    x = 78.51

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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.