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Finding the Fourth Proportional to 209.82, 312.50 and 208.61

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Solution

The fourth proportional to 209.82, 312.50 and 208.61 is: 310.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.82 : 312.50 = 208.61 : x
  2. Step 2: Convert to fraction form
    209.82/312.50 = 208.61/x
  3. Step 3: Cross multiply
    209.82x = 312.50 × 208.61
  4. Step 4: Simplify right side
    209.82x = 65,188.02
  5. Step 5: Solve for x
    x = 65,188.02/209.82
  6. Step 6: Final answer
    x = 310.69

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.