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Finding the Fourth Proportional to 455.40, 628.18 and 289.34

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Solution

The fourth proportional to 455.40, 628.18 and 289.34 is: 399.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    455.40 : 628.18 = 289.34 : x
  2. Step 2: Convert to fraction form
    455.40/628.18 = 289.34/x
  3. Step 3: Cross multiply
    455.40x = 628.18 × 289.34
  4. Step 4: Simplify right side
    455.40x = 181,757.60
  5. Step 5: Solve for x
    x = 181,757.60/455.40
  6. Step 6: Final answer
    x = 399.12

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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.