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Finding the Fourth Proportional to 1,278.30, 1,917 and 456.45

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Solution

The fourth proportional to 1,278.30, 1,917 and 456.45 is: 684.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.30 : 1,917 = 456.45 : x
  2. Step 2: Convert to fraction form
    1,278.30/1,917 = 456.45/x
  3. Step 3: Cross multiply
    1,278.30x = 1,917 × 456.45
  4. Step 4: Simplify right side
    1,278.30x = 875,014.65
  5. Step 5: Solve for x
    x = 875,014.65/1,278.30
  6. Step 6: Final answer
    x = 684.51

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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.