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Finding the Fourth Proportional to 1,278.79, 1,917.73 and 445.65

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Solution

The fourth proportional to 1,278.79, 1,917.73 and 445.65 is: 668.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.79 : 1,917.73 = 445.65 : x
  2. Step 2: Convert to fraction form
    1,278.79/1,917.73 = 445.65/x
  3. Step 3: Cross multiply
    1,278.79x = 1,917.73 × 445.65
  4. Step 4: Simplify right side
    1,278.79x = 854,636.37
  5. Step 5: Solve for x
    x = 854,636.37/1,278.79
  6. Step 6: Final answer
    x = 668.32

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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.