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Finding the Fourth Proportional to 216.80, 325.20 and 208.70

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Solution

The fourth proportional to 216.80, 325.20 and 208.70 is: 313.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.80 : 325.20 = 208.70 : x
  2. Step 2: Convert to fraction form
    216.80/325.20 = 208.70/x
  3. Step 3: Cross multiply
    216.80x = 325.20 × 208.70
  4. Step 4: Simplify right side
    216.80x = 67,869.24
  5. Step 5: Solve for x
    x = 67,869.24/216.80
  6. Step 6: Final answer
    x = 313.05

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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.