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Finding the Fourth Proportional to 811.61, 1,119.18 and 612.90

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Solution

The fourth proportional to 811.61, 1,119.18 and 612.90 is: 845.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.61 : 1,119.18 = 612.90 : x
  2. Step 2: Convert to fraction form
    811.61/1,119.18 = 612.90/x
  3. Step 3: Cross multiply
    811.61x = 1,119.18 × 612.90
  4. Step 4: Simplify right side
    811.61x = 685,945.42
  5. Step 5: Solve for x
    x = 685,945.42/811.61
  6. Step 6: Final answer
    x = 845.17

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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.