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Finding the Fourth Proportional to 258.40, 356.28 and 211.66

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Solution

The fourth proportional to 258.40, 356.28 and 211.66 is: 291.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.40 : 356.28 = 211.66 : x
  2. Step 2: Convert to fraction form
    258.40/356.28 = 211.66/x
  3. Step 3: Cross multiply
    258.40x = 356.28 × 211.66
  4. Step 4: Simplify right side
    258.40x = 75,410.22
  5. Step 5: Solve for x
    x = 75,410.22/258.40
  6. Step 6: Final answer
    x = 291.84

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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.