Home / 20,785.12-28,678.72-12,400

Finding the Fourth Proportional to 20,785.12, 28,678.72 and 12,400

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Solution

The fourth proportional to 20,785.12, 28,678.72 and 12,400 is: 17,109.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    20,785.12 : 28,678.72 = 12,400 : x
  2. Step 2: Convert to fraction form
    20,785.12/28,678.72 = 12,400/x
  3. Step 3: Cross multiply
    20,785.12x = 28,678.72 × 12,400
  4. Step 4: Simplify right side
    20,785.12x = 355,616,128
  5. Step 5: Solve for x
    x = 355,616,128/20,785.12
  6. Step 6: Final answer
    x = 17,109.17

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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.