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Finding the Fourth Proportional to 817.08, 1,226.70 and 643.20

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Solution

The fourth proportional to 817.08, 1,226.70 and 643.20 is: 965.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.08 : 1,226.70 = 643.20 : x
  2. Step 2: Convert to fraction form
    817.08/1,226.70 = 643.20/x
  3. Step 3: Cross multiply
    817.08x = 1,226.70 × 643.20
  4. Step 4: Simplify right side
    817.08x = 789,013.44
  5. Step 5: Solve for x
    x = 789,013.44/817.08
  6. Step 6: Final answer
    x = 965.65

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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.