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Finding the Fourth Proportional to 1,378.55, 1,901.93 and 780.97

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Solution

The fourth proportional to 1,378.55, 1,901.93 and 780.97 is: 1,077.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,378.55 : 1,901.93 = 780.97 : x
  2. Step 2: Convert to fraction form
    1,378.55/1,901.93 = 780.97/x
  3. Step 3: Cross multiply
    1,378.55x = 1,901.93 × 780.97
  4. Step 4: Simplify right side
    1,378.55x = 1,485,336.86
  5. Step 5: Solve for x
    x = 1,485,336.86/1,378.55
  6. Step 6: Final answer
    x = 1,077.46

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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.