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Finding the Fourth Proportional to 210.71, 316.09 and 80.75

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Solution

The fourth proportional to 210.71, 316.09 and 80.75 is: 121.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.71 : 316.09 = 80.75 : x
  2. Step 2: Convert to fraction form
    210.71/316.09 = 80.75/x
  3. Step 3: Cross multiply
    210.71x = 316.09 × 80.75
  4. Step 4: Simplify right side
    210.71x = 25,525.30
  5. Step 5: Solve for x
    x = 25,525.30/210.71
  6. Step 6: Final answer
    x = 121.14

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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.