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Finding the Fourth Proportional to 215.68, 323.53 and 78.68

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Solution

The fourth proportional to 215.68, 323.53 and 78.68 is: 118.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.68 : 323.53 = 78.68 : x
  2. Step 2: Convert to fraction form
    215.68/323.53 = 78.68/x
  3. Step 3: Cross multiply
    215.68x = 323.53 × 78.68
  4. Step 4: Simplify right side
    215.68x = 25,455.34
  5. Step 5: Solve for x
    x = 25,455.34/215.68
  6. Step 6: Final answer
    x = 118.02

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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.