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Finding the Fourth Proportional to 728.06, 1,085.94 and 611.15

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Solution

The fourth proportional to 728.06, 1,085.94 and 611.15 is: 911.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.06 : 1,085.94 = 611.15 : x
  2. Step 2: Convert to fraction form
    728.06/1,085.94 = 611.15/x
  3. Step 3: Cross multiply
    728.06x = 1,085.94 × 611.15
  4. Step 4: Simplify right side
    728.06x = 663,666.80
  5. Step 5: Solve for x
    x = 663,666.80/728.06
  6. Step 6: Final answer
    x = 911.56

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.