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Finding the Fourth Proportional to 260.88, 391.30 and 78.26

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Solution

The fourth proportional to 260.88, 391.30 and 78.26 is: 117.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.88 : 391.30 = 78.26 : x
  2. Step 2: Convert to fraction form
    260.88/391.30 = 78.26/x
  3. Step 3: Cross multiply
    260.88x = 391.30 × 78.26
  4. Step 4: Simplify right side
    260.88x = 30,623.14
  5. Step 5: Solve for x
    x = 30,623.14/260.88
  6. Step 6: Final answer
    x = 117.38

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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.