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Finding the Fourth Proportional to 699.80, 1,049.61 and 212.90

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Solution

The fourth proportional to 699.80, 1,049.61 and 212.90 is: 319.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    699.80 : 1,049.61 = 212.90 : x
  2. Step 2: Convert to fraction form
    699.80/1,049.61 = 212.90/x
  3. Step 3: Cross multiply
    699.80x = 1,049.61 × 212.90
  4. Step 4: Simplify right side
    699.80x = 223,461.97
  5. Step 5: Solve for x
    x = 223,461.97/699.80
  6. Step 6: Final answer
    x = 319.32

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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.