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Finding the Fourth Proportional to 1,387, 2,080.50 and 809.47

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Solution

The fourth proportional to 1,387, 2,080.50 and 809.47 is: 1,214.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,387 : 2,080.50 = 809.47 : x
  2. Step 2: Convert to fraction form
    1,387/2,080.50 = 809.47/x
  3. Step 3: Cross multiply
    1,387x = 2,080.50 × 809.47
  4. Step 4: Simplify right side
    1,387x = 1,684,102.34
  5. Step 5: Solve for x
    x = 1,684,102.34/1,387
  6. Step 6: Final answer
    x = 1,214.21

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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.