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Finding the Fourth Proportional to 838.40, 1,255.20 and 838.40

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Solution

The fourth proportional to 838.40, 1,255.20 and 838.40 is: 1,255.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.40 : 1,255.20 = 838.40 : x
  2. Step 2: Convert to fraction form
    838.40/1,255.20 = 838.40/x
  3. Step 3: Cross multiply
    838.40x = 1,255.20 × 838.40
  4. Step 4: Simplify right side
    838.40x = 1,052,359.68
  5. Step 5: Solve for x
    x = 1,052,359.68/838.40
  6. Step 6: Final answer
    x = 1,255.20

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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.