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Finding the Fourth Proportional to 279.81, 419.71 and 84.81

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Solution

The fourth proportional to 279.81, 419.71 and 84.81 is: 127.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.81 : 419.71 = 84.81 : x
  2. Step 2: Convert to fraction form
    279.81/419.71 = 84.81/x
  3. Step 3: Cross multiply
    279.81x = 419.71 × 84.81
  4. Step 4: Simplify right side
    279.81x = 35,593.29
  5. Step 5: Solve for x
    x = 35,593.29/279.81
  6. Step 6: Final answer
    x = 127.20

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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.