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Finding the Fourth Proportional to 1,311.56, 1,809.84 and 721.94

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Solution

The fourth proportional to 1,311.56, 1,809.84 and 721.94 is: 996.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,311.56 : 1,809.84 = 721.94 : x
  2. Step 2: Convert to fraction form
    1,311.56/1,809.84 = 721.94/x
  3. Step 3: Cross multiply
    1,311.56x = 1,809.84 × 721.94
  4. Step 4: Simplify right side
    1,311.56x = 1,306,595.89
  5. Step 5: Solve for x
    x = 1,306,595.89/1,311.56
  6. Step 6: Final answer
    x = 996.22

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1.5x scale

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.