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Finding the Fourth Proportional to 398.56, 550.32 and 258.78

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Solution

The fourth proportional to 398.56, 550.32 and 258.78 is: 357.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.56 : 550.32 = 258.78 : x
  2. Step 2: Convert to fraction form
    398.56/550.32 = 258.78/x
  3. Step 3: Cross multiply
    398.56x = 550.32 × 258.78
  4. Step 4: Simplify right side
    398.56x = 142,411.81
  5. Step 5: Solve for x
    x = 142,411.81/398.56
  6. Step 6: Final answer
    x = 357.32

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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.