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Finding the Fourth Proportional to 321.86, 442.89 and 290.81

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Solution

The fourth proportional to 321.86, 442.89 and 290.81 is: 400.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.86 : 442.89 = 290.81 : x
  2. Step 2: Convert to fraction form
    321.86/442.89 = 290.81/x
  3. Step 3: Cross multiply
    321.86x = 442.89 × 290.81
  4. Step 4: Simplify right side
    321.86x = 128,797.95
  5. Step 5: Solve for x
    x = 128,797.95/321.86
  6. Step 6: Final answer
    x = 400.16

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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.