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Finding the Fourth Proportional to 811.40, 1,119.31 and 614.57

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Solution

The fourth proportional to 811.40, 1,119.31 and 614.57 is: 847.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.40 : 1,119.31 = 614.57 : x
  2. Step 2: Convert to fraction form
    811.40/1,119.31 = 614.57/x
  3. Step 3: Cross multiply
    811.40x = 1,119.31 × 614.57
  4. Step 4: Simplify right side
    811.40x = 687,894.35
  5. Step 5: Solve for x
    x = 687,894.35/811.40
  6. Step 6: Final answer
    x = 847.79

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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.