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Finding the Fourth Proportional to 258.10, 386.93 and 121.21

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Solution

The fourth proportional to 258.10, 386.93 and 121.21 is: 181.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.10 : 386.93 = 121.21 : x
  2. Step 2: Convert to fraction form
    258.10/386.93 = 121.21/x
  3. Step 3: Cross multiply
    258.10x = 386.93 × 121.21
  4. Step 4: Simplify right side
    258.10x = 46,899.12
  5. Step 5: Solve for x
    x = 46,899.12/258.10
  6. Step 6: Final answer
    x = 181.71

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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.