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Finding the Fourth Proportional to 813.98, 1,221.20 and 443.71

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Solution

The fourth proportional to 813.98, 1,221.20 and 443.71 is: 665.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.98 : 1,221.20 = 443.71 : x
  2. Step 2: Convert to fraction form
    813.98/1,221.20 = 443.71/x
  3. Step 3: Cross multiply
    813.98x = 1,221.20 × 443.71
  4. Step 4: Simplify right side
    813.98x = 541,858.65
  5. Step 5: Solve for x
    x = 541,858.65/813.98
  6. Step 6: Final answer
    x = 665.69

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Double scale
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1.5x scale

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.