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Finding the Fourth Proportional to 258.40, 386.80 and 242.56

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Solution

The fourth proportional to 258.40, 386.80 and 242.56 is: 363.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.40 : 386.80 = 242.56 : x
  2. Step 2: Convert to fraction form
    258.40/386.80 = 242.56/x
  3. Step 3: Cross multiply
    258.40x = 386.80 × 242.56
  4. Step 4: Simplify right side
    258.40x = 93,822.21
  5. Step 5: Solve for x
    x = 93,822.21/258.40
  6. Step 6: Final answer
    x = 363.09

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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.