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Finding the Fourth Proportional to 1,287.39, 1,776.63 and 727.87

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Solution

The fourth proportional to 1,287.39, 1,776.63 and 727.87 is: 1,004.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.39 : 1,776.63 = 727.87 : x
  2. Step 2: Convert to fraction form
    1,287.39/1,776.63 = 727.87/x
  3. Step 3: Cross multiply
    1,287.39x = 1,776.63 × 727.87
  4. Step 4: Simplify right side
    1,287.39x = 1,293,155.68
  5. Step 5: Solve for x
    x = 1,293,155.68/1,287.39
  6. Step 6: Final answer
    x = 1,004.48

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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.