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Finding the Fourth Proportional to 212.79, 319.48 and 209.15

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Solution

The fourth proportional to 212.79, 319.48 and 209.15 is: 314.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.79 : 319.48 = 209.15 : x
  2. Step 2: Convert to fraction form
    212.79/319.48 = 209.15/x
  3. Step 3: Cross multiply
    212.79x = 319.48 × 209.15
  4. Step 4: Simplify right side
    212.79x = 66,817.12
  5. Step 5: Solve for x
    x = 66,817.12/212.79
  6. Step 6: Final answer
    x = 314.00

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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.