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Finding the Fourth Proportional to 172.65, 258.78 and 121.32

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Solution

The fourth proportional to 172.65, 258.78 and 121.32 is: 181.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.65 : 258.78 = 121.32 : x
  2. Step 2: Convert to fraction form
    172.65/258.78 = 121.32/x
  3. Step 3: Cross multiply
    172.65x = 258.78 × 121.32
  4. Step 4: Simplify right side
    172.65x = 31,395.19
  5. Step 5: Solve for x
    x = 31,395.19/172.65
  6. Step 6: Final answer
    x = 181.84

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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.