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Finding the Fourth Proportional to 70.21, 96.87 and 64.39

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Solution

The fourth proportional to 70.21, 96.87 and 64.39 is: 88.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.21 : 96.87 = 64.39 : x
  2. Step 2: Convert to fraction form
    70.21/96.87 = 64.39/x
  3. Step 3: Cross multiply
    70.21x = 96.87 × 64.39
  4. Step 4: Simplify right side
    70.21x = 6,237.22
  5. Step 5: Solve for x
    x = 6,237.22/70.21
  6. Step 6: Final answer
    x = 88.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.