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Finding the Fourth Proportional to 212.57, 318.80 and 75.65

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Solution

The fourth proportional to 212.57, 318.80 and 75.65 is: 113.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.57 : 318.80 = 75.65 : x
  2. Step 2: Convert to fraction form
    212.57/318.80 = 75.65/x
  3. Step 3: Cross multiply
    212.57x = 318.80 × 75.65
  4. Step 4: Simplify right side
    212.57x = 24,115.82
  5. Step 5: Solve for x
    x = 24,115.82/212.57
  6. Step 6: Final answer
    x = 113.45

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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.