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Finding the Fourth Proportional to 1,080.81, 1,491.89 and 638.65

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Solution

The fourth proportional to 1,080.81, 1,491.89 and 638.65 is: 881.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,080.81 : 1,491.89 = 638.65 : x
  2. Step 2: Convert to fraction form
    1,080.81/1,491.89 = 638.65/x
  3. Step 3: Cross multiply
    1,080.81x = 1,491.89 × 638.65
  4. Step 4: Simplify right side
    1,080.81x = 952,794.22
  5. Step 5: Solve for x
    x = 952,794.22/1,080.81
  6. Step 6: Final answer
    x = 881.56

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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.