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Finding the Fourth Proportional to 216.86, 322.86 and 215.78

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Solution

The fourth proportional to 216.86, 322.86 and 215.78 is: 321.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.86 : 322.86 = 215.78 : x
  2. Step 2: Convert to fraction form
    216.86/322.86 = 215.78/x
  3. Step 3: Cross multiply
    216.86x = 322.86 × 215.78
  4. Step 4: Simplify right side
    216.86x = 69,665.65
  5. Step 5: Solve for x
    x = 69,665.65/216.86
  6. Step 6: Final answer
    x = 321.25

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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.