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Finding the Fourth Proportional to 216.90, 325.16 and 79.87

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Solution

The fourth proportional to 216.90, 325.16 and 79.87 is: 119.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.90 : 325.16 = 79.87 : x
  2. Step 2: Convert to fraction form
    216.90/325.16 = 79.87/x
  3. Step 3: Cross multiply
    216.90x = 325.16 × 79.87
  4. Step 4: Simplify right side
    216.90x = 25,970.13
  5. Step 5: Solve for x
    x = 25,970.13/216.90
  6. Step 6: Final answer
    x = 119.74

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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.