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Finding the Fourth Proportional to 261.08, 391.08 and 217.64

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Solution

The fourth proportional to 261.08, 391.08 and 217.64 is: 326.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.08 : 391.08 = 217.64 : x
  2. Step 2: Convert to fraction form
    261.08/391.08 = 217.64/x
  3. Step 3: Cross multiply
    261.08x = 391.08 × 217.64
  4. Step 4: Simplify right side
    261.08x = 85,114.65
  5. Step 5: Solve for x
    x = 85,114.65/261.08
  6. Step 6: Final answer
    x = 326.01

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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.