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Finding the Fourth Proportional to 86.70, 119.64 and 49.87

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Solution

The fourth proportional to 86.70, 119.64 and 49.87 is: 68.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.70 : 119.64 = 49.87 : x
  2. Step 2: Convert to fraction form
    86.70/119.64 = 49.87/x
  3. Step 3: Cross multiply
    86.70x = 119.64 × 49.87
  4. Step 4: Simplify right side
    86.70x = 5,966.15
  5. Step 5: Solve for x
    x = 5,966.15/86.70
  6. Step 6: Final answer
    x = 68.81

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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.