Home / 21,165.78-31,720.81-11,810.20

Finding the Fourth Proportional to 21,165.78, 31,720.81 and 11,810.20

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Solution

The fourth proportional to 21,165.78, 31,720.81 and 11,810.20 is: 17,699.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    21,165.78 : 31,720.81 = 11,810.20 : x
  2. Step 2: Convert to fraction form
    21,165.78/31,720.81 = 11,810.20/x
  3. Step 3: Cross multiply
    21,165.78x = 31,720.81 × 11,810.20
  4. Step 4: Simplify right side
    21,165.78x = 374,629,110.26
  5. Step 5: Solve for x
    x = 374,629,110.26/21,165.78
  6. Step 6: Final answer
    x = 17,699.75

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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.