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Finding the Fourth Proportional to 280.71, 387.34 and 156.36

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Solution

The fourth proportional to 280.71, 387.34 and 156.36 is: 215.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.71 : 387.34 = 156.36 : x
  2. Step 2: Convert to fraction form
    280.71/387.34 = 156.36/x
  3. Step 3: Cross multiply
    280.71x = 387.34 × 156.36
  4. Step 4: Simplify right side
    280.71x = 60,564.48
  5. Step 5: Solve for x
    x = 60,564.48/280.71
  6. Step 6: Final answer
    x = 215.75

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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.