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Finding the Fourth Proportional to 280.68, 420.62 and 261.51

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Solution

The fourth proportional to 280.68, 420.62 and 261.51 is: 391.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.68 : 420.62 = 261.51 : x
  2. Step 2: Convert to fraction form
    280.68/420.62 = 261.51/x
  3. Step 3: Cross multiply
    280.68x = 420.62 × 261.51
  4. Step 4: Simplify right side
    280.68x = 109,995.03
  5. Step 5: Solve for x
    x = 109,995.03/280.68
  6. Step 6: Final answer
    x = 391.89

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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.