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Finding the Fourth Proportional to 207.15, 310.47 and 85.38

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Solution

The fourth proportional to 207.15, 310.47 and 85.38 is: 127.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.15 : 310.47 = 85.38 : x
  2. Step 2: Convert to fraction form
    207.15/310.47 = 85.38/x
  3. Step 3: Cross multiply
    207.15x = 310.47 × 85.38
  4. Step 4: Simplify right side
    207.15x = 26,507.93
  5. Step 5: Solve for x
    x = 26,507.93/207.15
  6. Step 6: Final answer
    x = 127.96

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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.