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Finding the Fourth Proportional to 642.55, 964.21 and 272.34

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Solution

The fourth proportional to 642.55, 964.21 and 272.34 is: 408.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.55 : 964.21 = 272.34 : x
  2. Step 2: Convert to fraction form
    642.55/964.21 = 272.34/x
  3. Step 3: Cross multiply
    642.55x = 964.21 × 272.34
  4. Step 4: Simplify right side
    642.55x = 262,588.23
  5. Step 5: Solve for x
    x = 262,588.23/642.55
  6. Step 6: Final answer
    x = 408.67

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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.