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Finding the Fourth Proportional to 209.12, 313.54 and 100.85

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Solution

The fourth proportional to 209.12, 313.54 and 100.85 is: 151.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.12 : 313.54 = 100.85 : x
  2. Step 2: Convert to fraction form
    209.12/313.54 = 100.85/x
  3. Step 3: Cross multiply
    209.12x = 313.54 × 100.85
  4. Step 4: Simplify right side
    209.12x = 31,618.69
  5. Step 5: Solve for x
    x = 31,618.69/209.12
  6. Step 6: Final answer
    x = 151.20

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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.