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Finding the Fourth Proportional to 289.05, 399.39 and 278.67

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Solution

The fourth proportional to 289.05, 399.39 and 278.67 is: 385.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.05 : 399.39 = 278.67 : x
  2. Step 2: Convert to fraction form
    289.05/399.39 = 278.67/x
  3. Step 3: Cross multiply
    289.05x = 399.39 × 278.67
  4. Step 4: Simplify right side
    289.05x = 111,298.01
  5. Step 5: Solve for x
    x = 111,298.01/289.05
  6. Step 6: Final answer
    x = 385.05

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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.