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Finding the Fourth Proportional to 211.79, 315.61 and 205.54

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Solution

The fourth proportional to 211.79, 315.61 and 205.54 is: 306.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.79 : 315.61 = 205.54 : x
  2. Step 2: Convert to fraction form
    211.79/315.61 = 205.54/x
  3. Step 3: Cross multiply
    211.79x = 315.61 × 205.54
  4. Step 4: Simplify right side
    211.79x = 64,870.48
  5. Step 5: Solve for x
    x = 64,870.48/211.79
  6. Step 6: Final answer
    x = 306.30

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.