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Finding the Fourth Proportional to 1,197.80, 1,796.70 and 428.20

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Solution

The fourth proportional to 1,197.80, 1,796.70 and 428.20 is: 642.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,197.80 : 1,796.70 = 428.20 : x
  2. Step 2: Convert to fraction form
    1,197.80/1,796.70 = 428.20/x
  3. Step 3: Cross multiply
    1,197.80x = 1,796.70 × 428.20
  4. Step 4: Simplify right side
    1,197.80x = 769,346.94
  5. Step 5: Solve for x
    x = 769,346.94/1,197.80
  6. Step 6: Final answer
    x = 642.30

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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.