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Finding the Fourth Proportional to 318.56, 438.80 and 285.84

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Solution

The fourth proportional to 318.56, 438.80 and 285.84 is: 393.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.56 : 438.80 = 285.84 : x
  2. Step 2: Convert to fraction form
    318.56/438.80 = 285.84/x
  3. Step 3: Cross multiply
    318.56x = 438.80 × 285.84
  4. Step 4: Simplify right side
    318.56x = 125,426.59
  5. Step 5: Solve for x
    x = 125,426.59/318.56
  6. Step 6: Final answer
    x = 393.73

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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.