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Finding the Fourth Proportional to 208.41, 312.63 and 86.70

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Solution

The fourth proportional to 208.41, 312.63 and 86.70 is: 130.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.41 : 312.63 = 86.70 : x
  2. Step 2: Convert to fraction form
    208.41/312.63 = 86.70/x
  3. Step 3: Cross multiply
    208.41x = 312.63 × 86.70
  4. Step 4: Simplify right side
    208.41x = 27,105.02
  5. Step 5: Solve for x
    x = 27,105.02/208.41
  6. Step 6: Final answer
    x = 130.06

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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.