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Finding the Fourth Proportional to 279.72, 421.75 and 261.16

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Solution

The fourth proportional to 279.72, 421.75 and 261.16 is: 393.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.72 : 421.75 = 261.16 : x
  2. Step 2: Convert to fraction form
    279.72/421.75 = 261.16/x
  3. Step 3: Cross multiply
    279.72x = 421.75 × 261.16
  4. Step 4: Simplify right side
    279.72x = 110,144.23
  5. Step 5: Solve for x
    x = 110,144.23/279.72
  6. Step 6: Final answer
    x = 393.77

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.