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Finding the Fourth Proportional to 285.74, 428.58 and 80.30

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Solution

The fourth proportional to 285.74, 428.58 and 80.30 is: 120.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.74 : 428.58 = 80.30 : x
  2. Step 2: Convert to fraction form
    285.74/428.58 = 80.30/x
  3. Step 3: Cross multiply
    285.74x = 428.58 × 80.30
  4. Step 4: Simplify right side
    285.74x = 34,416.05
  5. Step 5: Solve for x
    x = 34,416.05/285.74
  6. Step 6: Final answer
    x = 120.45

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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.