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Finding the Fourth Proportional to 64.38, 96.57 and 21.05

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Solution

The fourth proportional to 64.38, 96.57 and 21.05 is: 31.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.38 : 96.57 = 21.05 : x
  2. Step 2: Convert to fraction form
    64.38/96.57 = 21.05/x
  3. Step 3: Cross multiply
    64.38x = 96.57 × 21.05
  4. Step 4: Simplify right side
    64.38x = 2,032.36
  5. Step 5: Solve for x
    x = 2,032.36/64.38
  6. Step 6: Final answer
    x = 31.57

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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.