Home / 1,311.45-1,809.72-787.77

Finding the Fourth Proportional to 1,311.45, 1,809.72 and 787.77

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Solution

The fourth proportional to 1,311.45, 1,809.72 and 787.77 is: 1,087.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,311.45 : 1,809.72 = 787.77 : x
  2. Step 2: Convert to fraction form
    1,311.45/1,809.72 = 787.77/x
  3. Step 3: Cross multiply
    1,311.45x = 1,809.72 × 787.77
  4. Step 4: Simplify right side
    1,311.45x = 1,425,643.12
  5. Step 5: Solve for x
    x = 1,425,643.12/1,311.45
  6. Step 6: Final answer
    x = 1,087.07

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.