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Finding the Fourth Proportional to 280.76, 387.41 and 156.42

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Solution

The fourth proportional to 280.76, 387.41 and 156.42 is: 215.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.76 : 387.41 = 156.42 : x
  2. Step 2: Convert to fraction form
    280.76/387.41 = 156.42/x
  3. Step 3: Cross multiply
    280.76x = 387.41 × 156.42
  4. Step 4: Simplify right side
    280.76x = 60,597.89
  5. Step 5: Solve for x
    x = 60,597.89/280.76
  6. Step 6: Final answer
    x = 215.84

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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.