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Finding the Fourth Proportional to 261.26, 391.34 and 212.28

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Solution

The fourth proportional to 261.26, 391.34 and 212.28 is: 317.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.26 : 391.34 = 212.28 : x
  2. Step 2: Convert to fraction form
    261.26/391.34 = 212.28/x
  3. Step 3: Cross multiply
    261.26x = 391.34 × 212.28
  4. Step 4: Simplify right side
    261.26x = 83,072.59
  5. Step 5: Solve for x
    x = 83,072.59/261.26
  6. Step 6: Final answer
    x = 317.97

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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.