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Finding the Fourth Proportional to 1,351.38, 1,865.70 and 978

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Solution

The fourth proportional to 1,351.38, 1,865.70 and 978 is: 1,350.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,351.38 : 1,865.70 = 978 : x
  2. Step 2: Convert to fraction form
    1,351.38/1,865.70 = 978/x
  3. Step 3: Cross multiply
    1,351.38x = 1,865.70 × 978
  4. Step 4: Simplify right side
    1,351.38x = 1,824,654.60
  5. Step 5: Solve for x
    x = 1,824,654.60/1,351.38
  6. Step 6: Final answer
    x = 1,350.22

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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.