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Finding the Fourth Proportional to 258.30, 387.16 and 121.06

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Solution

The fourth proportional to 258.30, 387.16 and 121.06 is: 181.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.30 : 387.16 = 121.06 : x
  2. Step 2: Convert to fraction form
    258.30/387.16 = 121.06/x
  3. Step 3: Cross multiply
    258.30x = 387.16 × 121.06
  4. Step 4: Simplify right side
    258.30x = 46,869.59
  5. Step 5: Solve for x
    x = 46,869.59/258.30
  6. Step 6: Final answer
    x = 181.45

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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.