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Finding the Fourth Proportional to 521.16, 781.65 and 261.07

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Solution

The fourth proportional to 521.16, 781.65 and 261.07 is: 391.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.16 : 781.65 = 261.07 : x
  2. Step 2: Convert to fraction form
    521.16/781.65 = 261.07/x
  3. Step 3: Cross multiply
    521.16x = 781.65 × 261.07
  4. Step 4: Simplify right side
    521.16x = 204,065.37
  5. Step 5: Solve for x
    x = 204,065.37/521.16
  6. Step 6: Final answer
    x = 391.56

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.