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Finding the Fourth Proportional to 279.79, 419.69 and 74.38

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Solution

The fourth proportional to 279.79, 419.69 and 74.38 is: 111.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.79 : 419.69 = 74.38 : x
  2. Step 2: Convert to fraction form
    279.79/419.69 = 74.38/x
  3. Step 3: Cross multiply
    279.79x = 419.69 × 74.38
  4. Step 4: Simplify right side
    279.79x = 31,216.54
  5. Step 5: Solve for x
    x = 31,216.54/279.79
  6. Step 6: Final answer
    x = 111.57

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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.