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Finding the Fourth Proportional to 258.39, 355.59 and 218.90

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Solution

The fourth proportional to 258.39, 355.59 and 218.90 is: 301.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.39 : 355.59 = 218.90 : x
  2. Step 2: Convert to fraction form
    258.39/355.59 = 218.90/x
  3. Step 3: Cross multiply
    258.39x = 355.59 × 218.90
  4. Step 4: Simplify right side
    258.39x = 77,839.54
  5. Step 5: Solve for x
    x = 77,839.54/258.39
  6. Step 6: Final answer
    x = 301.25

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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.