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Finding the Fourth Proportional to 839.40, 1,256.70 and 743.40

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Solution

The fourth proportional to 839.40, 1,256.70 and 743.40 is: 1,112.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.40 : 1,256.70 = 743.40 : x
  2. Step 2: Convert to fraction form
    839.40/1,256.70 = 743.40/x
  3. Step 3: Cross multiply
    839.40x = 1,256.70 × 743.40
  4. Step 4: Simplify right side
    839.40x = 934,230.78
  5. Step 5: Solve for x
    x = 934,230.78/839.40
  6. Step 6: Final answer
    x = 1,112.97

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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.