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Finding the Fourth Proportional to 850.20, 1,275.60 and 820.20

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Solution

The fourth proportional to 850.20, 1,275.60 and 820.20 is: 1,230.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    850.20 : 1,275.60 = 820.20 : x
  2. Step 2: Convert to fraction form
    850.20/1,275.60 = 820.20/x
  3. Step 3: Cross multiply
    850.20x = 1,275.60 × 820.20
  4. Step 4: Simplify right side
    850.20x = 1,046,247.12
  5. Step 5: Solve for x
    x = 1,046,247.12/850.20
  6. Step 6: Final answer
    x = 1,230.59

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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.