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Finding the Fourth Proportional to 318.12, 438.78 and 207.69

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Solution

The fourth proportional to 318.12, 438.78 and 207.69 is: 286.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.12 : 438.78 = 207.69 : x
  2. Step 2: Convert to fraction form
    318.12/438.78 = 207.69/x
  3. Step 3: Cross multiply
    318.12x = 438.78 × 207.69
  4. Step 4: Simplify right side
    318.12x = 91,130.22
  5. Step 5: Solve for x
    x = 91,130.22/318.12
  6. Step 6: Final answer
    x = 286.46

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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.