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Finding the Fourth Proportional to 212.25, 318.39 and 209.55

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Solution

The fourth proportional to 212.25, 318.39 and 209.55 is: 314.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.25 : 318.39 = 209.55 : x
  2. Step 2: Convert to fraction form
    212.25/318.39 = 209.55/x
  3. Step 3: Cross multiply
    212.25x = 318.39 × 209.55
  4. Step 4: Simplify right side
    212.25x = 66,718.62
  5. Step 5: Solve for x
    x = 66,718.62/212.25
  6. Step 6: Final answer
    x = 314.34

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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.