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Finding the Fourth Proportional to 1,210.71, 1,815.24 and 820.71

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Solution

The fourth proportional to 1,210.71, 1,815.24 and 820.71 is: 1,230.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,210.71 : 1,815.24 = 820.71 : x
  2. Step 2: Convert to fraction form
    1,210.71/1,815.24 = 820.71/x
  3. Step 3: Cross multiply
    1,210.71x = 1,815.24 × 820.71
  4. Step 4: Simplify right side
    1,210.71x = 1,489,785.62
  5. Step 5: Solve for x
    x = 1,489,785.62/1,210.71
  6. Step 6: Final answer
    x = 1,230.51

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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.