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Finding the Fourth Proportional to 209.04, 313.41 and 87.21

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Solution

The fourth proportional to 209.04, 313.41 and 87.21 is: 130.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.04 : 313.41 = 87.21 : x
  2. Step 2: Convert to fraction form
    209.04/313.41 = 87.21/x
  3. Step 3: Cross multiply
    209.04x = 313.41 × 87.21
  4. Step 4: Simplify right side
    209.04x = 27,330.92
  5. Step 5: Solve for x
    x = 27,330.92/209.04
  6. Step 6: Final answer
    x = 130.74

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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.