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Finding the Fourth Proportional to 287.40, 396.90 and 238.64

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Solution

The fourth proportional to 287.40, 396.90 and 238.64 is: 329.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.40 : 396.90 = 238.64 : x
  2. Step 2: Convert to fraction form
    287.40/396.90 = 238.64/x
  3. Step 3: Cross multiply
    287.40x = 396.90 × 238.64
  4. Step 4: Simplify right side
    287.40x = 94,716.22
  5. Step 5: Solve for x
    x = 94,716.22/287.40
  6. Step 6: Final answer
    x = 329.56

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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.