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Finding the Fourth Proportional to 415.40, 623.10 and 318.20

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Solution

The fourth proportional to 415.40, 623.10 and 318.20 is: 477.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    415.40 : 623.10 = 318.20 : x
  2. Step 2: Convert to fraction form
    415.40/623.10 = 318.20/x
  3. Step 3: Cross multiply
    415.40x = 623.10 × 318.20
  4. Step 4: Simplify right side
    415.40x = 198,270.42
  5. Step 5: Solve for x
    x = 198,270.42/415.40
  6. Step 6: Final answer
    x = 477.30

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.