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Finding the Fourth Proportional to 1,278.06, 1,917.69 and 628.75

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Solution

The fourth proportional to 1,278.06, 1,917.69 and 628.75 is: 943.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.06 : 1,917.69 = 628.75 : x
  2. Step 2: Convert to fraction form
    1,278.06/1,917.69 = 628.75/x
  3. Step 3: Cross multiply
    1,278.06x = 1,917.69 × 628.75
  4. Step 4: Simplify right side
    1,278.06x = 1,205,747.59
  5. Step 5: Solve for x
    x = 1,205,747.59/1,278.06
  6. Step 6: Final answer
    x = 943.42

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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.