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Finding the Fourth Proportional to 279.72, 419.68 and 84.74

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Solution

The fourth proportional to 279.72, 419.68 and 84.74 is: 127.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.72 : 419.68 = 84.74 : x
  2. Step 2: Convert to fraction form
    279.72/419.68 = 84.74/x
  3. Step 3: Cross multiply
    279.72x = 419.68 × 84.74
  4. Step 4: Simplify right side
    279.72x = 35,561.69
  5. Step 5: Solve for x
    x = 35,561.69/279.72
  6. Step 6: Final answer
    x = 127.13

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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.