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Finding the Fourth Proportional to 419.55, 629.40 and 145.65

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Solution

The fourth proportional to 419.55, 629.40 and 145.65 is: 218.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.55 : 629.40 = 145.65 : x
  2. Step 2: Convert to fraction form
    419.55/629.40 = 145.65/x
  3. Step 3: Cross multiply
    419.55x = 629.40 × 145.65
  4. Step 4: Simplify right side
    419.55x = 91,672.11
  5. Step 5: Solve for x
    x = 91,672.11/419.55
  6. Step 6: Final answer
    x = 218.50

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.