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Finding the Fourth Proportional to 209.19, 313.82 and 79.20

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Solution

The fourth proportional to 209.19, 313.82 and 79.20 is: 118.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.19 : 313.82 = 79.20 : x
  2. Step 2: Convert to fraction form
    209.19/313.82 = 79.20/x
  3. Step 3: Cross multiply
    209.19x = 313.82 × 79.20
  4. Step 4: Simplify right side
    209.19x = 24,854.45
  5. Step 5: Solve for x
    x = 24,854.45/209.19
  6. Step 6: Final answer
    x = 118.81

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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.