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Finding the Fourth Proportional to 1,380.31, 2,070.80 and 455.81

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Solution

The fourth proportional to 1,380.31, 2,070.80 and 455.81 is: 683.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,380.31 : 2,070.80 = 455.81 : x
  2. Step 2: Convert to fraction form
    1,380.31/2,070.80 = 455.81/x
  3. Step 3: Cross multiply
    1,380.31x = 2,070.80 × 455.81
  4. Step 4: Simplify right side
    1,380.31x = 943,891.35
  5. Step 5: Solve for x
    x = 943,891.35/1,380.31
  6. Step 6: Final answer
    x = 683.83

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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.