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Finding the Fourth Proportional to 1,986.21, 2,979.32 and 505.43

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Solution

The fourth proportional to 1,986.21, 2,979.32 and 505.43 is: 758.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,986.21 : 2,979.32 = 505.43 : x
  2. Step 2: Convert to fraction form
    1,986.21/2,979.32 = 505.43/x
  3. Step 3: Cross multiply
    1,986.21x = 2,979.32 × 505.43
  4. Step 4: Simplify right side
    1,986.21x = 1,505,837.71
  5. Step 5: Solve for x
    x = 1,505,837.71/1,986.21
  6. Step 6: Final answer
    x = 758.15

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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.