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Finding the Fourth Proportional to 839.26, 1,256.55 and 427.51

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Solution

The fourth proportional to 839.26, 1,256.55 and 427.51 is: 640.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.26 : 1,256.55 = 427.51 : x
  2. Step 2: Convert to fraction form
    839.26/1,256.55 = 427.51/x
  3. Step 3: Cross multiply
    839.26x = 1,256.55 × 427.51
  4. Step 4: Simplify right side
    839.26x = 537,187.69
  5. Step 5: Solve for x
    x = 537,187.69/839.26
  6. Step 6: Final answer
    x = 640.07

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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.