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Finding the Fourth Proportional to 304.78, 420.66 and 280.18

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Solution

The fourth proportional to 304.78, 420.66 and 280.18 is: 386.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    304.78 : 420.66 = 280.18 : x
  2. Step 2: Convert to fraction form
    304.78/420.66 = 280.18/x
  3. Step 3: Cross multiply
    304.78x = 420.66 × 280.18
  4. Step 4: Simplify right side
    304.78x = 117,860.52
  5. Step 5: Solve for x
    x = 117,860.52/304.78
  6. Step 6: Final answer
    x = 386.71

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.