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Finding the Fourth Proportional to 465.30, 642.21 and 318

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Solution

The fourth proportional to 465.30, 642.21 and 318 is: 438.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    465.30 : 642.21 = 318 : x
  2. Step 2: Convert to fraction form
    465.30/642.21 = 318/x
  3. Step 3: Cross multiply
    465.30x = 642.21 × 318
  4. Step 4: Simplify right side
    465.30x = 204,222.78
  5. Step 5: Solve for x
    x = 204,222.78/465.30
  6. Step 6: Final answer
    x = 438.91

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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.