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Finding the Fourth Proportional to 208.86, 312.80 and 105.89

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Solution

The fourth proportional to 208.86, 312.80 and 105.89 is: 158.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.86 : 312.80 = 105.89 : x
  2. Step 2: Convert to fraction form
    208.86/312.80 = 105.89/x
  3. Step 3: Cross multiply
    208.86x = 312.80 × 105.89
  4. Step 4: Simplify right side
    208.86x = 33,121.86
  5. Step 5: Solve for x
    x = 33,121.86/208.86
  6. Step 6: Final answer
    x = 158.59

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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.