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Finding the Fourth Proportional to 209.70, 312.21 and 209.70

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Solution

The fourth proportional to 209.70, 312.21 and 209.70 is: 312.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.70 : 312.21 = 209.70 : x
  2. Step 2: Convert to fraction form
    209.70/312.21 = 209.70/x
  3. Step 3: Cross multiply
    209.70x = 312.21 × 209.70
  4. Step 4: Simplify right side
    209.70x = 65,470.44
  5. Step 5: Solve for x
    x = 65,470.44/209.70
  6. Step 6: Final answer
    x = 312.21

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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.