Home / 1,421.20-1,961.30-791.80

Finding the Fourth Proportional to 1,421.20, 1,961.30 and 791.80

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Solution

The fourth proportional to 1,421.20, 1,961.30 and 791.80 is: 1,092.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.20 : 1,961.30 = 791.80 : x
  2. Step 2: Convert to fraction form
    1,421.20/1,961.30 = 791.80/x
  3. Step 3: Cross multiply
    1,421.20x = 1,961.30 × 791.80
  4. Step 4: Simplify right side
    1,421.20x = 1,552,957.34
  5. Step 5: Solve for x
    x = 1,552,957.34/1,421.20
  6. Step 6: Final answer
    x = 1,092.71

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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.