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Finding the Fourth Proportional to 838.59, 1,257.90 and 405.64

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Solution

The fourth proportional to 838.59, 1,257.90 and 405.64 is: 608.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.59 : 1,257.90 = 405.64 : x
  2. Step 2: Convert to fraction form
    838.59/1,257.90 = 405.64/x
  3. Step 3: Cross multiply
    838.59x = 1,257.90 × 405.64
  4. Step 4: Simplify right side
    838.59x = 510,254.56
  5. Step 5: Solve for x
    x = 510,254.56/838.59
  6. Step 6: Final answer
    x = 608.47

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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.