Home / 1,286.42-1,928.40-420.14

Finding the Fourth Proportional to 1,286.42, 1,928.40 and 420.14

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Solution

The fourth proportional to 1,286.42, 1,928.40 and 420.14 is: 629.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,286.42 : 1,928.40 = 420.14 : x
  2. Step 2: Convert to fraction form
    1,286.42/1,928.40 = 420.14/x
  3. Step 3: Cross multiply
    1,286.42x = 1,928.40 × 420.14
  4. Step 4: Simplify right side
    1,286.42x = 810,197.98
  5. Step 5: Solve for x
    x = 810,197.98/1,286.42
  6. Step 6: Final answer
    x = 629.81

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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.