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Finding the Fourth Proportional to 285.39, 427.80 and 111.90

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Solution

The fourth proportional to 285.39, 427.80 and 111.90 is: 167.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.39 : 427.80 = 111.90 : x
  2. Step 2: Convert to fraction form
    285.39/427.80 = 111.90/x
  3. Step 3: Cross multiply
    285.39x = 427.80 × 111.90
  4. Step 4: Simplify right side
    285.39x = 47,870.82
  5. Step 5: Solve for x
    x = 47,870.82/285.39
  6. Step 6: Final answer
    x = 167.74

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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.