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Finding the Fourth Proportional to 209.08, 313.68 and 128.44

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Solution

The fourth proportional to 209.08, 313.68 and 128.44 is: 192.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.08 : 313.68 = 128.44 : x
  2. Step 2: Convert to fraction form
    209.08/313.68 = 128.44/x
  3. Step 3: Cross multiply
    209.08x = 313.68 × 128.44
  4. Step 4: Simplify right side
    209.08x = 40,289.06
  5. Step 5: Solve for x
    x = 40,289.06/209.08
  6. Step 6: Final answer
    x = 192.70

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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.