Home / 1,389.62-1,917.49-768.66

Finding the Fourth Proportional to 1,389.62, 1,917.49 and 768.66

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Solution

The fourth proportional to 1,389.62, 1,917.49 and 768.66 is: 1,060.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.62 : 1,917.49 = 768.66 : x
  2. Step 2: Convert to fraction form
    1,389.62/1,917.49 = 768.66/x
  3. Step 3: Cross multiply
    1,389.62x = 1,917.49 × 768.66
  4. Step 4: Simplify right side
    1,389.62x = 1,473,897.86
  5. Step 5: Solve for x
    x = 1,473,897.86/1,389.62
  6. Step 6: Final answer
    x = 1,060.65

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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.