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Finding the Fourth Proportional to 258.44, 387.60 and 121.40

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Solution

The fourth proportional to 258.44, 387.60 and 121.40 is: 182.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.44 : 387.60 = 121.40 : x
  2. Step 2: Convert to fraction form
    258.44/387.60 = 121.40/x
  3. Step 3: Cross multiply
    258.44x = 387.60 × 121.40
  4. Step 4: Simplify right side
    258.44x = 47,054.64
  5. Step 5: Solve for x
    x = 47,054.64/258.44
  6. Step 6: Final answer
    x = 182.07

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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.