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Finding the Fourth Proportional to 1,338.60, 1,847.09 and 778.64

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Solution

The fourth proportional to 1,338.60, 1,847.09 and 778.64 is: 1,074.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,338.60 : 1,847.09 = 778.64 : x
  2. Step 2: Convert to fraction form
    1,338.60/1,847.09 = 778.64/x
  3. Step 3: Cross multiply
    1,338.60x = 1,847.09 × 778.64
  4. Step 4: Simplify right side
    1,338.60x = 1,438,205.03
  5. Step 5: Solve for x
    x = 1,438,205.03/1,338.60
  6. Step 6: Final answer
    x = 1,074.41

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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.