Home / 1,419.31-2,129.45-639.85

Finding the Fourth Proportional to 1,419.31, 2,129.45 and 639.85

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Solution

The fourth proportional to 1,419.31, 2,129.45 and 639.85 is: 959.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,419.31 : 2,129.45 = 639.85 : x
  2. Step 2: Convert to fraction form
    1,419.31/2,129.45 = 639.85/x
  3. Step 3: Cross multiply
    1,419.31x = 2,129.45 × 639.85
  4. Step 4: Simplify right side
    1,419.31x = 1,362,528.58
  5. Step 5: Solve for x
    x = 1,362,528.58/1,419.31
  6. Step 6: Final answer
    x = 959.99

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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.