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Finding the Fourth Proportional to 1,139.36, 1,708.97 and 408.74

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Solution

The fourth proportional to 1,139.36, 1,708.97 and 408.74 is: 613.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,139.36 : 1,708.97 = 408.74 : x
  2. Step 2: Convert to fraction form
    1,139.36/1,708.97 = 408.74/x
  3. Step 3: Cross multiply
    1,139.36x = 1,708.97 × 408.74
  4. Step 4: Simplify right side
    1,139.36x = 698,513.81
  5. Step 5: Solve for x
    x = 698,513.81/1,139.36
  6. Step 6: Final answer
    x = 613.08

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.