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Finding the Fourth Proportional to 1,281.50, 1,921.23 and 665.30

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Solution

The fourth proportional to 1,281.50, 1,921.23 and 665.30 is: 997.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,281.50 : 1,921.23 = 665.30 : x
  2. Step 2: Convert to fraction form
    1,281.50/1,921.23 = 665.30/x
  3. Step 3: Cross multiply
    1,281.50x = 1,921.23 × 665.30
  4. Step 4: Simplify right side
    1,281.50x = 1,278,194.32
  5. Step 5: Solve for x
    x = 1,278,194.32/1,281.50
  6. Step 6: Final answer
    x = 997.42

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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.