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Finding the Fourth Proportional to 212.32, 318.57 and 90.55

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Solution

The fourth proportional to 212.32, 318.57 and 90.55 is: 135.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.32 : 318.57 = 90.55 : x
  2. Step 2: Convert to fraction form
    212.32/318.57 = 90.55/x
  3. Step 3: Cross multiply
    212.32x = 318.57 × 90.55
  4. Step 4: Simplify right side
    212.32x = 28,846.51
  5. Step 5: Solve for x
    x = 28,846.51/212.32
  6. Step 6: Final answer
    x = 135.86

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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.