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Finding the Fourth Proportional to 645.81, 891.23 and 351.09

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Solution

The fourth proportional to 645.81, 891.23 and 351.09 is: 484.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.81 : 891.23 = 351.09 : x
  2. Step 2: Convert to fraction form
    645.81/891.23 = 351.09/x
  3. Step 3: Cross multiply
    645.81x = 891.23 × 351.09
  4. Step 4: Simplify right side
    645.81x = 312,900.19
  5. Step 5: Solve for x
    x = 312,900.19/645.81
  6. Step 6: Final answer
    x = 484.51

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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.