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Finding the Fourth Proportional to 891.95, 1,231.30 and 636.60

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Solution

The fourth proportional to 891.95, 1,231.30 and 636.60 is: 878.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.95 : 1,231.30 = 636.60 : x
  2. Step 2: Convert to fraction form
    891.95/1,231.30 = 636.60/x
  3. Step 3: Cross multiply
    891.95x = 1,231.30 × 636.60
  4. Step 4: Simplify right side
    891.95x = 783,845.58
  5. Step 5: Solve for x
    x = 783,845.58/891.95
  6. Step 6: Final answer
    x = 878.80

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.