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Finding the Fourth Proportional to 318.80, 439.79 and 275.06

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Solution

The fourth proportional to 318.80, 439.79 and 275.06 is: 379.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.80 : 439.79 = 275.06 : x
  2. Step 2: Convert to fraction form
    318.80/439.79 = 275.06/x
  3. Step 3: Cross multiply
    318.80x = 439.79 × 275.06
  4. Step 4: Simplify right side
    318.80x = 120,968.36
  5. Step 5: Solve for x
    x = 120,968.36/318.80
  6. Step 6: Final answer
    x = 379.45

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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.