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Finding the Fourth Proportional to 839.10, 1,256.70 and 664.61

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Solution

The fourth proportional to 839.10, 1,256.70 and 664.61 is: 995.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.10 : 1,256.70 = 664.61 : x
  2. Step 2: Convert to fraction form
    839.10/1,256.70 = 664.61/x
  3. Step 3: Cross multiply
    839.10x = 1,256.70 × 664.61
  4. Step 4: Simplify right side
    839.10x = 835,218.53
  5. Step 5: Solve for x
    x = 835,218.53/839.10
  6. Step 6: Final answer
    x = 995.37

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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.