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Finding the Fourth Proportional to 838.40, 1,255.36 and 665.60

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Solution

The fourth proportional to 838.40, 1,255.36 and 665.60 is: 996.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.40 : 1,255.36 = 665.60 : x
  2. Step 2: Convert to fraction form
    838.40/1,255.36 = 665.60/x
  3. Step 3: Cross multiply
    838.40x = 1,255.36 × 665.60
  4. Step 4: Simplify right side
    838.40x = 835,567.62
  5. Step 5: Solve for x
    x = 835,567.62/838.40
  6. Step 6: Final answer
    x = 996.62

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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.