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Finding the Fourth Proportional to 811.66, 1,120.20 and 480.28

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Solution

The fourth proportional to 811.66, 1,120.20 and 480.28 is: 662.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.66 : 1,120.20 = 480.28 : x
  2. Step 2: Convert to fraction form
    811.66/1,120.20 = 480.28/x
  3. Step 3: Cross multiply
    811.66x = 1,120.20 × 480.28
  4. Step 4: Simplify right side
    811.66x = 538,009.66
  5. Step 5: Solve for x
    x = 538,009.66/811.66
  6. Step 6: Final answer
    x = 662.85

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Double scale
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1.5x scale

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.