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Finding the Fourth Proportional to 291.21, 401.59 and 287.42

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Solution

The fourth proportional to 291.21, 401.59 and 287.42 is: 396.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.21 : 401.59 = 287.42 : x
  2. Step 2: Convert to fraction form
    291.21/401.59 = 287.42/x
  3. Step 3: Cross multiply
    291.21x = 401.59 × 287.42
  4. Step 4: Simplify right side
    291.21x = 115,423.35
  5. Step 5: Solve for x
    x = 115,423.35/291.21
  6. Step 6: Final answer
    x = 396.36

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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.