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Finding the Fourth Proportional to 289.81, 399.70 and 218.60

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Solution

The fourth proportional to 289.81, 399.70 and 218.60 is: 301.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.81 : 399.70 = 218.60 : x
  2. Step 2: Convert to fraction form
    289.81/399.70 = 218.60/x
  3. Step 3: Cross multiply
    289.81x = 399.70 × 218.60
  4. Step 4: Simplify right side
    289.81x = 87,374.42
  5. Step 5: Solve for x
    x = 87,374.42/289.81
  6. Step 6: Final answer
    x = 301.49

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.