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Finding the Fourth Proportional to 172.40, 258.64 and 64.20

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Solution

The fourth proportional to 172.40, 258.64 and 64.20 is: 96.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.40 : 258.64 = 64.20 : x
  2. Step 2: Convert to fraction form
    172.40/258.64 = 64.20/x
  3. Step 3: Cross multiply
    172.40x = 258.64 × 64.20
  4. Step 4: Simplify right side
    172.40x = 16,604.69
  5. Step 5: Solve for x
    x = 16,604.69/172.40
  6. Step 6: Final answer
    x = 96.31

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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.