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Finding the Fourth Proportional to 1,991.88, 2,987.82 and 605.21

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Solution

The fourth proportional to 1,991.88, 2,987.82 and 605.21 is: 907.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,991.88 : 2,987.82 = 605.21 : x
  2. Step 2: Convert to fraction form
    1,991.88/2,987.82 = 605.21/x
  3. Step 3: Cross multiply
    1,991.88x = 2,987.82 × 605.21
  4. Step 4: Simplify right side
    1,991.88x = 1,808,248.05
  5. Step 5: Solve for x
    x = 1,808,248.05/1,991.88
  6. Step 6: Final answer
    x = 907.81

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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.