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Finding the Fourth Proportional to 645.94, 891.39 and 351.21

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Solution

The fourth proportional to 645.94, 891.39 and 351.21 is: 484.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.94 : 891.39 = 351.21 : x
  2. Step 2: Convert to fraction form
    645.94/891.39 = 351.21/x
  3. Step 3: Cross multiply
    645.94x = 891.39 × 351.21
  4. Step 4: Simplify right side
    645.94x = 313,067.31
  5. Step 5: Solve for x
    x = 313,067.31/645.94
  6. Step 6: Final answer
    x = 484.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.