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Finding the Fourth Proportional to 212.64, 320.65 and 209.75

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Solution

The fourth proportional to 212.64, 320.65 and 209.75 is: 316.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.64 : 320.65 = 209.75 : x
  2. Step 2: Convert to fraction form
    212.64/320.65 = 209.75/x
  3. Step 3: Cross multiply
    212.64x = 320.65 × 209.75
  4. Step 4: Simplify right side
    212.64x = 67,254.21
  5. Step 5: Solve for x
    x = 67,254.21/212.64
  6. Step 6: Final answer
    x = 316.29

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.