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Finding the Fourth Proportional to 1,620.90, 2,430.09 and 840.60

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Solution

The fourth proportional to 1,620.90, 2,430.09 and 840.60 is: 1,260.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,620.90 : 2,430.09 = 840.60 : x
  2. Step 2: Convert to fraction form
    1,620.90/2,430.09 = 840.60/x
  3. Step 3: Cross multiply
    1,620.90x = 2,430.09 × 840.60
  4. Step 4: Simplify right side
    1,620.90x = 2,042,733.65
  5. Step 5: Solve for x
    x = 2,042,733.65/1,620.90
  6. Step 6: Final answer
    x = 1,260.25

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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.