Home / 1,286.36-1,929.66-420.76

Finding the Fourth Proportional to 1,286.36, 1,929.66 and 420.76

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Solution

The fourth proportional to 1,286.36, 1,929.66 and 420.76 is: 631.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,286.36 : 1,929.66 = 420.76 : x
  2. Step 2: Convert to fraction form
    1,286.36/1,929.66 = 420.76/x
  3. Step 3: Cross multiply
    1,286.36x = 1,929.66 × 420.76
  4. Step 4: Simplify right side
    1,286.36x = 811,923.74
  5. Step 5: Solve for x
    x = 811,923.74/1,286.36
  6. Step 6: Final answer
    x = 631.18

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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.