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Finding the Fourth Proportional to 780.95, 1,171.04 and 260.78

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Solution

The fourth proportional to 780.95, 1,171.04 and 260.78 is: 391.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.95 : 1,171.04 = 260.78 : x
  2. Step 2: Convert to fraction form
    780.95/1,171.04 = 260.78/x
  3. Step 3: Cross multiply
    780.95x = 1,171.04 × 260.78
  4. Step 4: Simplify right side
    780.95x = 305,378.61
  5. Step 5: Solve for x
    x = 305,378.61/780.95
  6. Step 6: Final answer
    x = 391.03

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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.