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Finding the Fourth Proportional to 155.28, 214.28 and 85.34

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Solution

The fourth proportional to 155.28, 214.28 and 85.34 is: 117.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.28 : 214.28 = 85.34 : x
  2. Step 2: Convert to fraction form
    155.28/214.28 = 85.34/x
  3. Step 3: Cross multiply
    155.28x = 214.28 × 85.34
  4. Step 4: Simplify right side
    155.28x = 18,285.74
  5. Step 5: Solve for x
    x = 18,285.74/155.28
  6. Step 6: Final answer
    x = 117.76

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.