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Finding the Fourth Proportional to 427.65, 639.87 and 253.67

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Solution

The fourth proportional to 427.65, 639.87 and 253.67 is: 379.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.65 : 639.87 = 253.67 : x
  2. Step 2: Convert to fraction form
    427.65/639.87 = 253.67/x
  3. Step 3: Cross multiply
    427.65x = 639.87 × 253.67
  4. Step 4: Simplify right side
    427.65x = 162,312.62
  5. Step 5: Solve for x
    x = 162,312.62/427.65
  6. Step 6: Final answer
    x = 379.55

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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.