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Finding the Fourth Proportional to 391.01, 585.45 and 261.21

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Solution

The fourth proportional to 391.01, 585.45 and 261.21 is: 391.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.01 : 585.45 = 261.21 : x
  2. Step 2: Convert to fraction form
    391.01/585.45 = 261.21/x
  3. Step 3: Cross multiply
    391.01x = 585.45 × 261.21
  4. Step 4: Simplify right side
    391.01x = 152,925.39
  5. Step 5: Solve for x
    x = 152,925.39/391.01
  6. Step 6: Final answer
    x = 391.11

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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.