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Finding the Fourth Proportional to 279.90, 419.86 and 74.47

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Solution

The fourth proportional to 279.90, 419.86 and 74.47 is: 111.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.90 : 419.86 = 74.47 : x
  2. Step 2: Convert to fraction form
    279.90/419.86 = 74.47/x
  3. Step 3: Cross multiply
    279.90x = 419.86 × 74.47
  4. Step 4: Simplify right side
    279.90x = 31,266.97
  5. Step 5: Solve for x
    x = 31,266.97/279.90
  6. Step 6: Final answer
    x = 111.71

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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.