Home / 1,249.20-1,871.40-760.80

Finding the Fourth Proportional to 1,249.20, 1,871.40 and 760.80

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Solution

The fourth proportional to 1,249.20, 1,871.40 and 760.80 is: 1,139.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,249.20 : 1,871.40 = 760.80 : x
  2. Step 2: Convert to fraction form
    1,249.20/1,871.40 = 760.80/x
  3. Step 3: Cross multiply
    1,249.20x = 1,871.40 × 760.80
  4. Step 4: Simplify right side
    1,249.20x = 1,423,761.12
  5. Step 5: Solve for x
    x = 1,423,761.12/1,249.20
  6. Step 6: Final answer
    x = 1,139.74

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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.