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Finding the Fourth Proportional to 1,273.20, 1,754.76 and 978

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Solution

The fourth proportional to 1,273.20, 1,754.76 and 978 is: 1,347.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,273.20 : 1,754.76 = 978 : x
  2. Step 2: Convert to fraction form
    1,273.20/1,754.76 = 978/x
  3. Step 3: Cross multiply
    1,273.20x = 1,754.76 × 978
  4. Step 4: Simplify right side
    1,273.20x = 1,716,155.28
  5. Step 5: Solve for x
    x = 1,716,155.28/1,273.20
  6. Step 6: Final answer
    x = 1,347.91

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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.