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Finding the Fourth Proportional to 811.87, 1,120.64 and 480.28

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Solution

The fourth proportional to 811.87, 1,120.64 and 480.28 is: 662.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.87 : 1,120.64 = 480.28 : x
  2. Step 2: Convert to fraction form
    811.87/1,120.64 = 480.28/x
  3. Step 3: Cross multiply
    811.87x = 1,120.64 × 480.28
  4. Step 4: Simplify right side
    811.87x = 538,217.88
  5. Step 5: Solve for x
    x = 538,217.88/811.87
  6. Step 6: Final answer
    x = 662.93

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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.