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Finding the Fourth Proportional to 809.40, 1,211.70 and 713.40

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Solution

The fourth proportional to 809.40, 1,211.70 and 713.40 is: 1,067.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.40 : 1,211.70 = 713.40 : x
  2. Step 2: Convert to fraction form
    809.40/1,211.70 = 713.40/x
  3. Step 3: Cross multiply
    809.40x = 1,211.70 × 713.40
  4. Step 4: Simplify right side
    809.40x = 864,426.78
  5. Step 5: Solve for x
    x = 864,426.78/809.40
  6. Step 6: Final answer
    x = 1,067.98

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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.