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Finding the Fourth Proportional to 1,308.09, 1,805.19 and 978.03

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Solution

The fourth proportional to 1,308.09, 1,805.19 and 978.03 is: 1,349.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,308.09 : 1,805.19 = 978.03 : x
  2. Step 2: Convert to fraction form
    1,308.09/1,805.19 = 978.03/x
  3. Step 3: Cross multiply
    1,308.09x = 1,805.19 × 978.03
  4. Step 4: Simplify right side
    1,308.09x = 1,765,529.98
  5. Step 5: Solve for x
    x = 1,765,529.98/1,308.09
  6. Step 6: Final answer
    x = 1,349.70

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.