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Finding the Fourth Proportional to 838.78, 1,256.31 and 818.11

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Solution

The fourth proportional to 838.78, 1,256.31 and 818.11 is: 1,225.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.78 : 1,256.31 = 818.11 : x
  2. Step 2: Convert to fraction form
    838.78/1,256.31 = 818.11/x
  3. Step 3: Cross multiply
    838.78x = 1,256.31 × 818.11
  4. Step 4: Simplify right side
    838.78x = 1,027,799.77
  5. Step 5: Solve for x
    x = 1,027,799.77/838.78
  6. Step 6: Final answer
    x = 1,225.35

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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.