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Finding the Fourth Proportional to 1,376.31, 1,899.07 and 778.80

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Solution

The fourth proportional to 1,376.31, 1,899.07 and 778.80 is: 1,074.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,376.31 : 1,899.07 = 778.80 : x
  2. Step 2: Convert to fraction form
    1,376.31/1,899.07 = 778.80/x
  3. Step 3: Cross multiply
    1,376.31x = 1,899.07 × 778.80
  4. Step 4: Simplify right side
    1,376.31x = 1,478,991.82
  5. Step 5: Solve for x
    x = 1,478,991.82/1,376.31
  6. Step 6: Final answer
    x = 1,074.61

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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.