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Finding the Fourth Proportional to 212.29, 318.58 and 90.64

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Solution

The fourth proportional to 212.29, 318.58 and 90.64 is: 136.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.29 : 318.58 = 90.64 : x
  2. Step 2: Convert to fraction form
    212.29/318.58 = 90.64/x
  3. Step 3: Cross multiply
    212.29x = 318.58 × 90.64
  4. Step 4: Simplify right side
    212.29x = 28,874.98
  5. Step 5: Solve for x
    x = 28,874.98/212.29
  6. Step 6: Final answer
    x = 136.02

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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.