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Finding the Fourth Proportional to 838.86, 1,258.32 and 261.78

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Solution

The fourth proportional to 838.86, 1,258.32 and 261.78 is: 392.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.86 : 1,258.32 = 261.78 : x
  2. Step 2: Convert to fraction form
    838.86/1,258.32 = 261.78/x
  3. Step 3: Cross multiply
    838.86x = 1,258.32 × 261.78
  4. Step 4: Simplify right side
    838.86x = 329,403.01
  5. Step 5: Solve for x
    x = 329,403.01/838.86
  6. Step 6: Final answer
    x = 392.68

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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.