Home / 1,305.20-1,789.11-1,287.70

Finding the Fourth Proportional to 1,305.20, 1,789.11 and 1,287.70

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Solution

The fourth proportional to 1,305.20, 1,789.11 and 1,287.70 is: 1,765.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,305.20 : 1,789.11 = 1,287.70 : x
  2. Step 2: Convert to fraction form
    1,305.20/1,789.11 = 1,287.70/x
  3. Step 3: Cross multiply
    1,305.20x = 1,789.11 × 1,287.70
  4. Step 4: Simplify right side
    1,305.20x = 2,303,832.47
  5. Step 5: Solve for x
    x = 2,303,832.47/1,305.20
  6. Step 6: Final answer
    x = 1,765.11

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.