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Finding the Fourth Proportional to 208.86, 312.96 and 135.51

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Solution

The fourth proportional to 208.86, 312.96 and 135.51 is: 203.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.86 : 312.96 = 135.51 : x
  2. Step 2: Convert to fraction form
    208.86/312.96 = 135.51/x
  3. Step 3: Cross multiply
    208.86x = 312.96 × 135.51
  4. Step 4: Simplify right side
    208.86x = 42,409.21
  5. Step 5: Solve for x
    x = 42,409.21/208.86
  6. Step 6: Final answer
    x = 203.05

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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.