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Finding the Fourth Proportional to 939.47, 1,409.20 and 290.05

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Solution

The fourth proportional to 939.47, 1,409.20 and 290.05 is: 435.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    939.47 : 1,409.20 = 290.05 : x
  2. Step 2: Convert to fraction form
    939.47/1,409.20 = 290.05/x
  3. Step 3: Cross multiply
    939.47x = 1,409.20 × 290.05
  4. Step 4: Simplify right side
    939.47x = 408,734.21
  5. Step 5: Solve for x
    x = 408,734.21/939.47
  6. Step 6: Final answer
    x = 435.07

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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.