Home / 21,005.80-31,508.70-19,985.20

Finding the Fourth Proportional to 21,005.80, 31,508.70 and 19,985.20

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Solution

The fourth proportional to 21,005.80, 31,508.70 and 19,985.20 is: 29,977.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    21,005.80 : 31,508.70 = 19,985.20 : x
  2. Step 2: Convert to fraction form
    21,005.80/31,508.70 = 19,985.20/x
  3. Step 3: Cross multiply
    21,005.80x = 31,508.70 × 19,985.20
  4. Step 4: Simplify right side
    21,005.80x = 629,707,671.24
  5. Step 5: Solve for x
    x = 629,707,671.24/21,005.80
  6. Step 6: Final answer
    x = 29,977.80

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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.