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Finding the Fourth Proportional to 608.40, 912.78 and 218.40

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Solution

The fourth proportional to 608.40, 912.78 and 218.40 is: 327.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    608.40 : 912.78 = 218.40 : x
  2. Step 2: Convert to fraction form
    608.40/912.78 = 218.40/x
  3. Step 3: Cross multiply
    608.40x = 912.78 × 218.40
  4. Step 4: Simplify right side
    608.40x = 199,351.15
  5. Step 5: Solve for x
    x = 199,351.15/608.40
  6. Step 6: Final answer
    x = 327.66

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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.