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Finding the Fourth Proportional to 1,980.90, 2,971.89 and 664.88

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Solution

The fourth proportional to 1,980.90, 2,971.89 and 664.88 is: 997.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,980.90 : 2,971.89 = 664.88 : x
  2. Step 2: Convert to fraction form
    1,980.90/2,971.89 = 664.88/x
  3. Step 3: Cross multiply
    1,980.90x = 2,971.89 × 664.88
  4. Step 4: Simplify right side
    1,980.90x = 1,975,935.36
  5. Step 5: Solve for x
    x = 1,975,935.36/1,980.90
  6. Step 6: Final answer
    x = 997.49

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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.