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Finding the Fourth Proportional to 210.64, 315.96 and 80.68

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Solution

The fourth proportional to 210.64, 315.96 and 80.68 is: 121.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.64 : 315.96 = 80.68 : x
  2. Step 2: Convert to fraction form
    210.64/315.96 = 80.68/x
  3. Step 3: Cross multiply
    210.64x = 315.96 × 80.68
  4. Step 4: Simplify right side
    210.64x = 25,491.65
  5. Step 5: Solve for x
    x = 25,491.65/210.64
  6. Step 6: Final answer
    x = 121.02

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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.