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Finding the Fourth Proportional to 811.28, 1,216.56 and 618.32

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Solution

The fourth proportional to 811.28, 1,216.56 and 618.32 is: 927.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.28 : 1,216.56 = 618.32 : x
  2. Step 2: Convert to fraction form
    811.28/1,216.56 = 618.32/x
  3. Step 3: Cross multiply
    811.28x = 1,216.56 × 618.32
  4. Step 4: Simplify right side
    811.28x = 752,223.38
  5. Step 5: Solve for x
    x = 752,223.38/811.28
  6. Step 6: Final answer
    x = 927.21

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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.