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Finding the Fourth Proportional to 378.09, 521.91 and 291.02

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Solution

The fourth proportional to 378.09, 521.91 and 291.02 is: 401.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.09 : 521.91 = 291.02 : x
  2. Step 2: Convert to fraction form
    378.09/521.91 = 291.02/x
  3. Step 3: Cross multiply
    378.09x = 521.91 × 291.02
  4. Step 4: Simplify right side
    378.09x = 151,883.64
  5. Step 5: Solve for x
    x = 151,883.64/378.09
  6. Step 6: Final answer
    x = 401.71

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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.