Home / 21,138.40-31,715.70-20,806.30

Finding the Fourth Proportional to 21,138.40, 31,715.70 and 20,806.30

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Solution

The fourth proportional to 21,138.40, 31,715.70 and 20,806.30 is: 31,217.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    21,138.40 : 31,715.70 = 20,806.30 : x
  2. Step 2: Convert to fraction form
    21,138.40/31,715.70 = 20,806.30/x
  3. Step 3: Cross multiply
    21,138.40x = 31,715.70 × 20,806.30
  4. Step 4: Simplify right side
    21,138.40x = 659,886,368.91
  5. Step 5: Solve for x
    x = 659,886,368.91/21,138.40
  6. Step 6: Final answer
    x = 31,217.42

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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.