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Finding the Fourth Proportional to 1,388.64, 2,083.26 and 980.40

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Solution

The fourth proportional to 1,388.64, 2,083.26 and 980.40 is: 1,470.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,388.64 : 2,083.26 = 980.40 : x
  2. Step 2: Convert to fraction form
    1,388.64/2,083.26 = 980.40/x
  3. Step 3: Cross multiply
    1,388.64x = 2,083.26 × 980.40
  4. Step 4: Simplify right side
    1,388.64x = 2,042,428.10
  5. Step 5: Solve for x
    x = 2,042,428.10/1,388.64
  6. Step 6: Final answer
    x = 1,470.81

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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.