Home / 1,286.64-1,929.56-420.75

Finding the Fourth Proportional to 1,286.64, 1,929.56 and 420.75

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Solution

The fourth proportional to 1,286.64, 1,929.56 and 420.75 is: 630.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,286.64 : 1,929.56 = 420.75 : x
  2. Step 2: Convert to fraction form
    1,286.64/1,929.56 = 420.75/x
  3. Step 3: Cross multiply
    1,286.64x = 1,929.56 × 420.75
  4. Step 4: Simplify right side
    1,286.64x = 811,860.27
  5. Step 5: Solve for x
    x = 811,860.27/1,286.64
  6. Step 6: Final answer
    x = 630.99

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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.