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Finding the Fourth Proportional to 465.40, 642.20 and 278.88

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Solution

The fourth proportional to 465.40, 642.20 and 278.88 is: 384.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    465.40 : 642.20 = 278.88 : x
  2. Step 2: Convert to fraction form
    465.40/642.20 = 278.88/x
  3. Step 3: Cross multiply
    465.40x = 642.20 × 278.88
  4. Step 4: Simplify right side
    465.40x = 179,096.74
  5. Step 5: Solve for x
    x = 179,096.74/465.40
  6. Step 6: Final answer
    x = 384.83

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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.