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Finding the Fourth Proportional to 640.05, 960.30 and 315.20

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Solution

The fourth proportional to 640.05, 960.30 and 315.20 is: 472.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.05 : 960.30 = 315.20 : x
  2. Step 2: Convert to fraction form
    640.05/960.30 = 315.20/x
  3. Step 3: Cross multiply
    640.05x = 960.30 × 315.20
  4. Step 4: Simplify right side
    640.05x = 302,681.76
  5. Step 5: Solve for x
    x = 302,681.76/640.05
  6. Step 6: Final answer
    x = 472.90

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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.