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Finding the Fourth Proportional to 258.64, 356.40 and 217.12

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Solution

The fourth proportional to 258.64, 356.40 and 217.12 is: 299.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.64 : 356.40 = 217.12 : x
  2. Step 2: Convert to fraction form
    258.64/356.40 = 217.12/x
  3. Step 3: Cross multiply
    258.64x = 356.40 × 217.12
  4. Step 4: Simplify right side
    258.64x = 77,381.57
  5. Step 5: Solve for x
    x = 77,381.57/258.64
  6. Step 6: Final answer
    x = 299.19

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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.