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Finding the Fourth Proportional to 209.80, 312.05 and 203.56

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Solution

The fourth proportional to 209.80, 312.05 and 203.56 is: 302.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.80 : 312.05 = 203.56 : x
  2. Step 2: Convert to fraction form
    209.80/312.05 = 203.56/x
  3. Step 3: Cross multiply
    209.80x = 312.05 × 203.56
  4. Step 4: Simplify right side
    209.80x = 63,520.90
  5. Step 5: Solve for x
    x = 63,520.90/209.80
  6. Step 6: Final answer
    x = 302.77

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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.