Home / 1,422.17-2,129.87-689.39

Finding the Fourth Proportional to 1,422.17, 2,129.87 and 689.39

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Solution

The fourth proportional to 1,422.17, 2,129.87 and 689.39 is: 1,032.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,422.17 : 2,129.87 = 689.39 : x
  2. Step 2: Convert to fraction form
    1,422.17/2,129.87 = 689.39/x
  3. Step 3: Cross multiply
    1,422.17x = 2,129.87 × 689.39
  4. Step 4: Simplify right side
    1,422.17x = 1,468,302.15
  5. Step 5: Solve for x
    x = 1,468,302.15/1,422.17
  6. Step 6: Final answer
    x = 1,032.44

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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.