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Finding the Fourth Proportional to 261.30, 392.20 and 213.10

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Solution

The fourth proportional to 261.30, 392.20 and 213.10 is: 319.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.30 : 392.20 = 213.10 : x
  2. Step 2: Convert to fraction form
    261.30/392.20 = 213.10/x
  3. Step 3: Cross multiply
    261.30x = 392.20 × 213.10
  4. Step 4: Simplify right side
    261.30x = 83,577.82
  5. Step 5: Solve for x
    x = 83,577.82/261.30
  6. Step 6: Final answer
    x = 319.85

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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.