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Finding the Fourth Proportional to 285.80, 428.53 and 90.75

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Solution

The fourth proportional to 285.80, 428.53 and 90.75 is: 136.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.80 : 428.53 = 90.75 : x
  2. Step 2: Convert to fraction form
    285.80/428.53 = 90.75/x
  3. Step 3: Cross multiply
    285.80x = 428.53 × 90.75
  4. Step 4: Simplify right side
    285.80x = 38,889.10
  5. Step 5: Solve for x
    x = 38,889.10/285.80
  6. Step 6: Final answer
    x = 136.07

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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.