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Finding the Fourth Proportional to 218.40, 321.60 and 218.40

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Solution

The fourth proportional to 218.40, 321.60 and 218.40 is: 321.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.40 : 321.60 = 218.40 : x
  2. Step 2: Convert to fraction form
    218.40/321.60 = 218.40/x
  3. Step 3: Cross multiply
    218.40x = 321.60 × 218.40
  4. Step 4: Simplify right side
    218.40x = 70,237.44
  5. Step 5: Solve for x
    x = 70,237.44/218.40
  6. Step 6: Final answer
    x = 321.60

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Why These Related Problems?

These problems maintain the same ratio (1.47) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.