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Finding the Fourth Proportional to 811.29, 1,119.96 and 612.21

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Solution

The fourth proportional to 811.29, 1,119.96 and 612.21 is: 845.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.29 : 1,119.96 = 612.21 : x
  2. Step 2: Convert to fraction form
    811.29/1,119.96 = 612.21/x
  3. Step 3: Cross multiply
    811.29x = 1,119.96 × 612.21
  4. Step 4: Simplify right side
    811.29x = 685,650.71
  5. Step 5: Solve for x
    x = 685,650.71/811.29
  6. Step 6: Final answer
    x = 845.14

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.