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Finding the Fourth Proportional to 211.79, 315.33 and 208.76

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Solution

The fourth proportional to 211.79, 315.33 and 208.76 is: 310.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.79 : 315.33 = 208.76 : x
  2. Step 2: Convert to fraction form
    211.79/315.33 = 208.76/x
  3. Step 3: Cross multiply
    211.79x = 315.33 × 208.76
  4. Step 4: Simplify right side
    211.79x = 65,825.93
  5. Step 5: Solve for x
    x = 65,825.93/211.79
  6. Step 6: Final answer
    x = 310.80

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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.