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Finding the Fourth Proportional to 838.21, 1,257.43 and 261.13

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Solution

The fourth proportional to 838.21, 1,257.43 and 261.13 is: 391.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.21 : 1,257.43 = 261.13 : x
  2. Step 2: Convert to fraction form
    838.21/1,257.43 = 261.13/x
  3. Step 3: Cross multiply
    838.21x = 1,257.43 × 261.13
  4. Step 4: Simplify right side
    838.21x = 328,345.76
  5. Step 5: Solve for x
    x = 328,345.76/838.21
  6. Step 6: Final answer
    x = 391.72

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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.