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Finding the Fourth Proportional to 811.61, 1,217.31 and 324.66

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Solution

The fourth proportional to 811.61, 1,217.31 and 324.66 is: 486.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.61 : 1,217.31 = 324.66 : x
  2. Step 2: Convert to fraction form
    811.61/1,217.31 = 324.66/x
  3. Step 3: Cross multiply
    811.61x = 1,217.31 × 324.66
  4. Step 4: Simplify right side
    811.61x = 395,210.65
  5. Step 5: Solve for x
    x = 395,210.65/811.61
  6. Step 6: Final answer
    x = 486.95

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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.