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Finding the Fourth Proportional to 207.42, 310.86 and 85.54

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Solution

The fourth proportional to 207.42, 310.86 and 85.54 is: 128.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.42 : 310.86 = 85.54 : x
  2. Step 2: Convert to fraction form
    207.42/310.86 = 85.54/x
  3. Step 3: Cross multiply
    207.42x = 310.86 × 85.54
  4. Step 4: Simplify right side
    207.42x = 26,590.96
  5. Step 5: Solve for x
    x = 26,590.96/207.42
  6. Step 6: Final answer
    x = 128.20

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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.