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Finding the Fourth Proportional to 811.77, 1,120.28 and 517.20

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Solution

The fourth proportional to 811.77, 1,120.28 and 517.20 is: 713.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.77 : 1,120.28 = 517.20 : x
  2. Step 2: Convert to fraction form
    811.77/1,120.28 = 517.20/x
  3. Step 3: Cross multiply
    811.77x = 1,120.28 × 517.20
  4. Step 4: Simplify right side
    811.77x = 579,406.23
  5. Step 5: Solve for x
    x = 579,406.23/811.77
  6. Step 6: Final answer
    x = 713.76

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Double scale
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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.