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Finding the Fourth Proportional to 328.38, 492.80 and 212.78

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Solution

The fourth proportional to 328.38, 492.80 and 212.78 is: 319.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.38 : 492.80 = 212.78 : x
  2. Step 2: Convert to fraction form
    328.38/492.80 = 212.78/x
  3. Step 3: Cross multiply
    328.38x = 492.80 × 212.78
  4. Step 4: Simplify right side
    328.38x = 104,857.98
  5. Step 5: Solve for x
    x = 104,857.98/328.38
  6. Step 6: Final answer
    x = 319.32

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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.