Home / 1,689.13-2,331.12-981.20

Finding the Fourth Proportional to 1,689.13, 2,331.12 and 981.20

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Solution

The fourth proportional to 1,689.13, 2,331.12 and 981.20 is: 1,354.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,689.13 : 2,331.12 = 981.20 : x
  2. Step 2: Convert to fraction form
    1,689.13/2,331.12 = 981.20/x
  3. Step 3: Cross multiply
    1,689.13x = 2,331.12 × 981.20
  4. Step 4: Simplify right side
    1,689.13x = 2,287,294.94
  5. Step 5: Solve for x
    x = 2,287,294.94/1,689.13
  6. Step 6: Final answer
    x = 1,354.13

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.