Home / 3,929-5,421.78-2,160.80

Finding the Fourth Proportional to 3,929, 5,421.78 and 2,160.80

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Solution

The fourth proportional to 3,929, 5,421.78 and 2,160.80 is: 2,981.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,929 : 5,421.78 = 2,160.80 : x
  2. Step 2: Convert to fraction form
    3,929/5,421.78 = 2,160.80/x
  3. Step 3: Cross multiply
    3,929x = 5,421.78 × 2,160.80
  4. Step 4: Simplify right side
    3,929x = 11,715,382.22
  5. Step 5: Solve for x
    x = 11,715,382.22/3,929
  6. Step 6: Final answer
    x = 2,981.77

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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.