Home / 1,405.11-2,107.66-431.21

Finding the Fourth Proportional to 1,405.11, 2,107.66 and 431.21

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Solution

The fourth proportional to 1,405.11, 2,107.66 and 431.21 is: 646.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,405.11 : 2,107.66 = 431.21 : x
  2. Step 2: Convert to fraction form
    1,405.11/2,107.66 = 431.21/x
  3. Step 3: Cross multiply
    1,405.11x = 2,107.66 × 431.21
  4. Step 4: Simplify right side
    1,405.11x = 908,838.43
  5. Step 5: Solve for x
    x = 908,838.43/1,405.11
  6. Step 6: Final answer
    x = 646.81

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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.