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Finding the Fourth Proportional to 261.42, 390.26 and 206.76

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Solution

The fourth proportional to 261.42, 390.26 and 206.76 is: 308.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.42 : 390.26 = 206.76 : x
  2. Step 2: Convert to fraction form
    261.42/390.26 = 206.76/x
  3. Step 3: Cross multiply
    261.42x = 390.26 × 206.76
  4. Step 4: Simplify right side
    261.42x = 80,689.12
  5. Step 5: Solve for x
    x = 80,689.12/261.42
  6. Step 6: Final answer
    x = 308.66

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.