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Finding the Fourth Proportional to 86.39, 119.19 and 51.40

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Solution

The fourth proportional to 86.39, 119.19 and 51.40 is: 70.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.39 : 119.19 = 51.40 : x
  2. Step 2: Convert to fraction form
    86.39/119.19 = 51.40/x
  3. Step 3: Cross multiply
    86.39x = 119.19 × 51.40
  4. Step 4: Simplify right side
    86.39x = 6,126.37
  5. Step 5: Solve for x
    x = 6,126.37/86.39
  6. Step 6: Final answer
    x = 70.92

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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.