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Finding the Fourth Proportional to 969.60, 1,338.94 and 620.90

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Solution

The fourth proportional to 969.60, 1,338.94 and 620.90 is: 857.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    969.60 : 1,338.94 = 620.90 : x
  2. Step 2: Convert to fraction form
    969.60/1,338.94 = 620.90/x
  3. Step 3: Cross multiply
    969.60x = 1,338.94 × 620.90
  4. Step 4: Simplify right side
    969.60x = 831,347.85
  5. Step 5: Solve for x
    x = 831,347.85/969.60
  6. Step 6: Final answer
    x = 857.41

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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.