Home / 1,420.19-2,129.36-679.40

Finding the Fourth Proportional to 1,420.19, 2,129.36 and 679.40

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Solution

The fourth proportional to 1,420.19, 2,129.36 and 679.40 is: 1,018.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420.19 : 2,129.36 = 679.40 : x
  2. Step 2: Convert to fraction form
    1,420.19/2,129.36 = 679.40/x
  3. Step 3: Cross multiply
    1,420.19x = 2,129.36 × 679.40
  4. Step 4: Simplify right side
    1,420.19x = 1,446,687.18
  5. Step 5: Solve for x
    x = 1,446,687.18/1,420.19
  6. Step 6: Final answer
    x = 1,018.66

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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.