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Finding the Fourth Proportional to 807.72, 1,211.40 and 320.82

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Solution

The fourth proportional to 807.72, 1,211.40 and 320.82 is: 481.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.72 : 1,211.40 = 320.82 : x
  2. Step 2: Convert to fraction form
    807.72/1,211.40 = 320.82/x
  3. Step 3: Cross multiply
    807.72x = 1,211.40 × 320.82
  4. Step 4: Simplify right side
    807.72x = 388,641.35
  5. Step 5: Solve for x
    x = 388,641.35/807.72
  6. Step 6: Final answer
    x = 481.16

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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.