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Finding the Fourth Proportional to 261.15, 390.80 and 210.12

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Solution

The fourth proportional to 261.15, 390.80 and 210.12 is: 314.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.15 : 390.80 = 210.12 : x
  2. Step 2: Convert to fraction form
    261.15/390.80 = 210.12/x
  3. Step 3: Cross multiply
    261.15x = 390.80 × 210.12
  4. Step 4: Simplify right side
    261.15x = 82,113.85
  5. Step 5: Solve for x
    x = 82,113.85/261.15
  6. Step 6: Final answer
    x = 314.43

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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.