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Finding the Fourth Proportional to 285.05, 427.26 and 138.80

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Solution

The fourth proportional to 285.05, 427.26 and 138.80 is: 208.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.05 : 427.26 = 138.80 : x
  2. Step 2: Convert to fraction form
    285.05/427.26 = 138.80/x
  3. Step 3: Cross multiply
    285.05x = 427.26 × 138.80
  4. Step 4: Simplify right side
    285.05x = 59,303.69
  5. Step 5: Solve for x
    x = 59,303.69/285.05
  6. Step 6: Final answer
    x = 208.05

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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.