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Finding the Fourth Proportional to 3,990, 5,985 and 1,681.68

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Solution

The fourth proportional to 3,990, 5,985 and 1,681.68 is: 2,522.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,990 : 5,985 = 1,681.68 : x
  2. Step 2: Convert to fraction form
    3,990/5,985 = 1,681.68/x
  3. Step 3: Cross multiply
    3,990x = 5,985 × 1,681.68
  4. Step 4: Simplify right side
    3,990x = 10,064,854.80
  5. Step 5: Solve for x
    x = 10,064,854.80/3,990
  6. Step 6: Final answer
    x = 2,522.52

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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.