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Finding the Fourth Proportional to 215.29, 322.98 and 78.43

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Solution

The fourth proportional to 215.29, 322.98 and 78.43 is: 117.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.29 : 322.98 = 78.43 : x
  2. Step 2: Convert to fraction form
    215.29/322.98 = 78.43/x
  3. Step 3: Cross multiply
    215.29x = 322.98 × 78.43
  4. Step 4: Simplify right side
    215.29x = 25,332.69
  5. Step 5: Solve for x
    x = 25,332.69/215.29
  6. Step 6: Final answer
    x = 117.67

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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.