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Finding the Fourth Proportional to 1,078.93, 1,489.11 and 636.80

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Solution

The fourth proportional to 1,078.93, 1,489.11 and 636.80 is: 878.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,078.93 : 1,489.11 = 636.80 : x
  2. Step 2: Convert to fraction form
    1,078.93/1,489.11 = 636.80/x
  3. Step 3: Cross multiply
    1,078.93x = 1,489.11 × 636.80
  4. Step 4: Simplify right side
    1,078.93x = 948,265.25
  5. Step 5: Solve for x
    x = 948,265.25/1,078.93
  6. Step 6: Final answer
    x = 878.89

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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.