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Finding the Fourth Proportional to 1,080.81, 1,491.08 and 687.69

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Solution

The fourth proportional to 1,080.81, 1,491.08 and 687.69 is: 948.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,080.81 : 1,491.08 = 687.69 : x
  2. Step 2: Convert to fraction form
    1,080.81/1,491.08 = 687.69/x
  3. Step 3: Cross multiply
    1,080.81x = 1,491.08 × 687.69
  4. Step 4: Simplify right side
    1,080.81x = 1,025,397.37
  5. Step 5: Solve for x
    x = 1,025,397.37/1,080.81
  6. Step 6: Final answer
    x = 948.73

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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.