Home / 21,009.20-31,513.80-18,705.20

Finding the Fourth Proportional to 21,009.20, 31,513.80 and 18,705.20

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Solution

The fourth proportional to 21,009.20, 31,513.80 and 18,705.20 is: 28,057.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    21,009.20 : 31,513.80 = 18,705.20 : x
  2. Step 2: Convert to fraction form
    21,009.20/31,513.80 = 18,705.20/x
  3. Step 3: Cross multiply
    21,009.20x = 31,513.80 × 18,705.20
  4. Step 4: Simplify right side
    21,009.20x = 589,471,931.76
  5. Step 5: Solve for x
    x = 589,471,931.76/21,009.20
  6. Step 6: Final answer
    x = 28,057.80

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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.