Home / 21,138.12-31,708.38-7,989.36

Finding the Fourth Proportional to 21,138.12, 31,708.38 and 7,989.36

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Solution

The fourth proportional to 21,138.12, 31,708.38 and 7,989.36 is: 11,984.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    21,138.12 : 31,708.38 = 7,989.36 : x
  2. Step 2: Convert to fraction form
    21,138.12/31,708.38 = 7,989.36/x
  3. Step 3: Cross multiply
    21,138.12x = 31,708.38 × 7,989.36
  4. Step 4: Simplify right side
    21,138.12x = 253,329,662.84
  5. Step 5: Solve for x
    x = 253,329,662.84/21,138.12
  6. Step 6: Final answer
    x = 11,984.49

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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.