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Finding the Fourth Proportional to 261.86, 393.19 and 208.19

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Solution

The fourth proportional to 261.86, 393.19 and 208.19 is: 312.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.86 : 393.19 = 208.19 : x
  2. Step 2: Convert to fraction form
    261.86/393.19 = 208.19/x
  3. Step 3: Cross multiply
    261.86x = 393.19 × 208.19
  4. Step 4: Simplify right side
    261.86x = 81,858.23
  5. Step 5: Solve for x
    x = 81,858.23/261.86
  6. Step 6: Final answer
    x = 312.60

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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.