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Finding the Fourth Proportional to 231.30, 345.90 and 172.78

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Solution

The fourth proportional to 231.30, 345.90 and 172.78 is: 258.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.30 : 345.90 = 172.78 : x
  2. Step 2: Convert to fraction form
    231.30/345.90 = 172.78/x
  3. Step 3: Cross multiply
    231.30x = 345.90 × 172.78
  4. Step 4: Simplify right side
    231.30x = 59,763.74
  5. Step 5: Solve for x
    x = 59,763.74/231.30
  6. Step 6: Final answer
    x = 258.38

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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.