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Finding the Fourth Proportional to 318.29, 438.88 and 287.20

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Solution

The fourth proportional to 318.29, 438.88 and 287.20 is: 396.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.29 : 438.88 = 287.20 : x
  2. Step 2: Convert to fraction form
    318.29/438.88 = 287.20/x
  3. Step 3: Cross multiply
    318.29x = 438.88 × 287.20
  4. Step 4: Simplify right side
    318.29x = 126,044.64
  5. Step 5: Solve for x
    x = 126,044.64/318.29
  6. Step 6: Final answer
    x = 396.00

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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.