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Finding the Fourth Proportional to 838.34, 1,257.81 and 399.72

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Solution

The fourth proportional to 838.34, 1,257.81 and 399.72 is: 599.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.34 : 1,257.81 = 399.72 : x
  2. Step 2: Convert to fraction form
    838.34/1,257.81 = 399.72/x
  3. Step 3: Cross multiply
    838.34x = 1,257.81 × 399.72
  4. Step 4: Simplify right side
    838.34x = 502,771.81
  5. Step 5: Solve for x
    x = 502,771.81/838.34
  6. Step 6: Final answer
    x = 599.73

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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.