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Finding the Fourth Proportional to 318.56, 438.54 and 285.80

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Solution

The fourth proportional to 318.56, 438.54 and 285.80 is: 393.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.56 : 438.54 = 285.80 : x
  2. Step 2: Convert to fraction form
    318.56/438.54 = 285.80/x
  3. Step 3: Cross multiply
    318.56x = 438.54 × 285.80
  4. Step 4: Simplify right side
    318.56x = 125,334.76
  5. Step 5: Solve for x
    x = 125,334.76/318.56
  6. Step 6: Final answer
    x = 393.44

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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.