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Finding the Fourth Proportional to 155.20, 214.16 and 89.72

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Solution

The fourth proportional to 155.20, 214.16 and 89.72 is: 123.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.20 : 214.16 = 89.72 : x
  2. Step 2: Convert to fraction form
    155.20/214.16 = 89.72/x
  3. Step 3: Cross multiply
    155.20x = 214.16 × 89.72
  4. Step 4: Simplify right side
    155.20x = 19,214.44
  5. Step 5: Solve for x
    x = 19,214.44/155.20
  6. Step 6: Final answer
    x = 123.80

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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.