Home / 20,989.80-31,491.90-9,311.40

Finding the Fourth Proportional to 20,989.80, 31,491.90 and 9,311.40

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Solution

The fourth proportional to 20,989.80, 31,491.90 and 9,311.40 is: 13,970.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    20,989.80 : 31,491.90 = 9,311.40 : x
  2. Step 2: Convert to fraction form
    20,989.80/31,491.90 = 9,311.40/x
  3. Step 3: Cross multiply
    20,989.80x = 31,491.90 × 9,311.40
  4. Step 4: Simplify right side
    20,989.80x = 293,233,677.66
  5. Step 5: Solve for x
    x = 293,233,677.66/20,989.80
  6. Step 6: Final answer
    x = 13,970.29

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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.