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Finding the Fourth Proportional to 1,329.87, 1,990.08 and 809.67

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Solution

The fourth proportional to 1,329.87, 1,990.08 and 809.67 is: 1,211.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,329.87 : 1,990.08 = 809.67 : x
  2. Step 2: Convert to fraction form
    1,329.87/1,990.08 = 809.67/x
  3. Step 3: Cross multiply
    1,329.87x = 1,990.08 × 809.67
  4. Step 4: Simplify right side
    1,329.87x = 1,611,308.07
  5. Step 5: Solve for x
    x = 1,611,308.07/1,329.87
  6. Step 6: Final answer
    x = 1,211.63

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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.