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Finding the Fourth Proportional to 1,986, 2,979.14 and 669.68

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Solution

The fourth proportional to 1,986, 2,979.14 and 669.68 is: 1,004.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,986 : 2,979.14 = 669.68 : x
  2. Step 2: Convert to fraction form
    1,986/2,979.14 = 669.68/x
  3. Step 3: Cross multiply
    1,986x = 2,979.14 × 669.68
  4. Step 4: Simplify right side
    1,986x = 1,995,070.48
  5. Step 5: Solve for x
    x = 1,995,070.48/1,986
  6. Step 6: Final answer
    x = 1,004.57

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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.