Home / 20,820.80-31,239.30-9,125.78

Finding the Fourth Proportional to 20,820.80, 31,239.30 and 9,125.78

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Solution

The fourth proportional to 20,820.80, 31,239.30 and 9,125.78 is: 13,692.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    20,820.80 : 31,239.30 = 9,125.78 : x
  2. Step 2: Convert to fraction form
    20,820.80/31,239.30 = 9,125.78/x
  3. Step 3: Cross multiply
    20,820.80x = 31,239.30 × 9,125.78
  4. Step 4: Simplify right side
    20,820.80x = 285,082,979.15
  5. Step 5: Solve for x
    x = 285,082,979.15/20,820.80
  6. Step 6: Final answer
    x = 13,692.22

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1.5x scale

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.