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Finding the Fourth Proportional to 212.08, 317.85 and 209.79

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Solution

The fourth proportional to 212.08, 317.85 and 209.79 is: 314.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.08 : 317.85 = 209.79 : x
  2. Step 2: Convert to fraction form
    212.08/317.85 = 209.79/x
  3. Step 3: Cross multiply
    212.08x = 317.85 × 209.79
  4. Step 4: Simplify right side
    212.08x = 66,681.75
  5. Step 5: Solve for x
    x = 66,681.75/212.08
  6. Step 6: Final answer
    x = 314.42

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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.