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Finding the Fourth Proportional to 811.10, 1,214.82 and 485.79

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Solution

The fourth proportional to 811.10, 1,214.82 and 485.79 is: 727.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.10 : 1,214.82 = 485.79 : x
  2. Step 2: Convert to fraction form
    811.10/1,214.82 = 485.79/x
  3. Step 3: Cross multiply
    811.10x = 1,214.82 × 485.79
  4. Step 4: Simplify right side
    811.10x = 590,147.41
  5. Step 5: Solve for x
    x = 590,147.41/811.10
  6. Step 6: Final answer
    x = 727.59

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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.