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Finding the Fourth Proportional to 818.40, 1,222.14 and 809.90

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Solution

The fourth proportional to 818.40, 1,222.14 and 809.90 is: 1,209.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.40 : 1,222.14 = 809.90 : x
  2. Step 2: Convert to fraction form
    818.40/1,222.14 = 809.90/x
  3. Step 3: Cross multiply
    818.40x = 1,222.14 × 809.90
  4. Step 4: Simplify right side
    818.40x = 989,805.08
  5. Step 5: Solve for x
    x = 989,805.08/818.40
  6. Step 6: Final answer
    x = 1,209.44

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.