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Finding the Fourth Proportional to 1,391.47, 2,085.83 and 611.89

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Solution

The fourth proportional to 1,391.47, 2,085.83 and 611.89 is: 917.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,391.47 : 2,085.83 = 611.89 : x
  2. Step 2: Convert to fraction form
    1,391.47/2,085.83 = 611.89/x
  3. Step 3: Cross multiply
    1,391.47x = 2,085.83 × 611.89
  4. Step 4: Simplify right side
    1,391.47x = 1,276,292.54
  5. Step 5: Solve for x
    x = 1,276,292.54/1,391.47
  6. Step 6: Final answer
    x = 917.23

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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.