Home / 1,291.20-1,781.78-767.13

Finding the Fourth Proportional to 1,291.20, 1,781.78 and 767.13

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Solution

The fourth proportional to 1,291.20, 1,781.78 and 767.13 is: 1,058.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,291.20 : 1,781.78 = 767.13 : x
  2. Step 2: Convert to fraction form
    1,291.20/1,781.78 = 767.13/x
  3. Step 3: Cross multiply
    1,291.20x = 1,781.78 × 767.13
  4. Step 4: Simplify right side
    1,291.20x = 1,366,853.06
  5. Step 5: Solve for x
    x = 1,366,853.06/1,291.20
  6. Step 6: Final answer
    x = 1,058.59

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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.