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Finding the Fourth Proportional to 305.53, 421.64 and 172.76

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Solution

The fourth proportional to 305.53, 421.64 and 172.76 is: 238.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.53 : 421.64 = 172.76 : x
  2. Step 2: Convert to fraction form
    305.53/421.64 = 172.76/x
  3. Step 3: Cross multiply
    305.53x = 421.64 × 172.76
  4. Step 4: Simplify right side
    305.53x = 72,840.20
  5. Step 5: Solve for x
    x = 72,840.20/305.53
  6. Step 6: Final answer
    x = 238.41

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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.