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Finding the Fourth Proportional to 80.40, 120.48 and 64.32

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Solution

The fourth proportional to 80.40, 120.48 and 64.32 is: 96.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.40 : 120.48 = 64.32 : x
  2. Step 2: Convert to fraction form
    80.40/120.48 = 64.32/x
  3. Step 3: Cross multiply
    80.40x = 120.48 × 64.32
  4. Step 4: Simplify right side
    80.40x = 7,749.27
  5. Step 5: Solve for x
    x = 7,749.27/80.40
  6. Step 6: Final answer
    x = 96.38

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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.