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Finding the Fourth Proportional to 3,990, 5,506.32 and 2,221.68

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Solution

The fourth proportional to 3,990, 5,506.32 and 2,221.68 is: 3,065.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,990 : 5,506.32 = 2,221.68 : x
  2. Step 2: Convert to fraction form
    3,990/5,506.32 = 2,221.68/x
  3. Step 3: Cross multiply
    3,990x = 5,506.32 × 2,221.68
  4. Step 4: Simplify right side
    3,990x = 12,233,281.02
  5. Step 5: Solve for x
    x = 12,233,281.02/3,990
  6. Step 6: Final answer
    x = 3,065.99

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1.5x scale

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.