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Finding the Fourth Proportional to 261.15, 391.91 and 210.41

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Solution

The fourth proportional to 261.15, 391.91 and 210.41 is: 315.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.15 : 391.91 = 210.41 : x
  2. Step 2: Convert to fraction form
    261.15/391.91 = 210.41/x
  3. Step 3: Cross multiply
    261.15x = 391.91 × 210.41
  4. Step 4: Simplify right side
    261.15x = 82,460.35
  5. Step 5: Solve for x
    x = 82,460.35/261.15
  6. Step 6: Final answer
    x = 315.76

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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.