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Finding the Fourth Proportional to 745.17, 1,117.18 and 420.09

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Solution

The fourth proportional to 745.17, 1,117.18 and 420.09 is: 629.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    745.17 : 1,117.18 = 420.09 : x
  2. Step 2: Convert to fraction form
    745.17/1,117.18 = 420.09/x
  3. Step 3: Cross multiply
    745.17x = 1,117.18 × 420.09
  4. Step 4: Simplify right side
    745.17x = 469,316.15
  5. Step 5: Solve for x
    x = 469,316.15/745.17
  6. Step 6: Final answer
    x = 629.81

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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.