Home / 1,291.31-1,780.60-1,021.66

Finding the Fourth Proportional to 1,291.31, 1,780.60 and 1,021.66

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Solution

The fourth proportional to 1,291.31, 1,780.60 and 1,021.66 is: 1,408.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,291.31 : 1,780.60 = 1,021.66 : x
  2. Step 2: Convert to fraction form
    1,291.31/1,780.60 = 1,021.66/x
  3. Step 3: Cross multiply
    1,291.31x = 1,780.60 × 1,021.66
  4. Step 4: Simplify right side
    1,291.31x = 1,819,175.78
  5. Step 5: Solve for x
    x = 1,819,175.78/1,291.31
  6. Step 6: Final answer
    x = 1,408.78

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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.