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Finding the Fourth Proportional to 258.88, 388.34 and 66.50

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Solution

The fourth proportional to 258.88, 388.34 and 66.50 is: 99.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.88 : 388.34 = 66.50 : x
  2. Step 2: Convert to fraction form
    258.88/388.34 = 66.50/x
  3. Step 3: Cross multiply
    258.88x = 388.34 × 66.50
  4. Step 4: Simplify right side
    258.88x = 25,824.28
  5. Step 5: Solve for x
    x = 25,824.28/258.88
  6. Step 6: Final answer
    x = 99.76

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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.