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Finding the Fourth Proportional to 155.30, 214.30 and 85.35

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Solution

The fourth proportional to 155.30, 214.30 and 85.35 is: 117.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.30 : 214.30 = 85.35 : x
  2. Step 2: Convert to fraction form
    155.30/214.30 = 85.35/x
  3. Step 3: Cross multiply
    155.30x = 214.30 × 85.35
  4. Step 4: Simplify right side
    155.30x = 18,290.94
  5. Step 5: Solve for x
    x = 18,290.94/155.30
  6. Step 6: Final answer
    x = 117.78

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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.