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Finding the Fourth Proportional to 455.64, 629.21 and 389.76

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Solution

The fourth proportional to 455.64, 629.21 and 389.76 is: 538.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    455.64 : 629.21 = 389.76 : x
  2. Step 2: Convert to fraction form
    455.64/629.21 = 389.76/x
  3. Step 3: Cross multiply
    455.64x = 629.21 × 389.76
  4. Step 4: Simplify right side
    455.64x = 245,240.89
  5. Step 5: Solve for x
    x = 245,240.89/455.64
  6. Step 6: Final answer
    x = 538.23

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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.