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Finding the Fourth Proportional to 947.50, 1,420.71 and 427.30

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Solution

The fourth proportional to 947.50, 1,420.71 and 427.30 is: 640.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    947.50 : 1,420.71 = 427.30 : x
  2. Step 2: Convert to fraction form
    947.50/1,420.71 = 427.30/x
  3. Step 3: Cross multiply
    947.50x = 1,420.71 × 427.30
  4. Step 4: Simplify right side
    947.50x = 607,069.38
  5. Step 5: Solve for x
    x = 607,069.38/947.50
  6. Step 6: Final answer
    x = 640.71

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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.