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Finding the Fourth Proportional to 285.99, 394.56 and 198.78

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Solution

The fourth proportional to 285.99, 394.56 and 198.78 is: 274.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.99 : 394.56 = 198.78 : x
  2. Step 2: Convert to fraction form
    285.99/394.56 = 198.78/x
  3. Step 3: Cross multiply
    285.99x = 394.56 × 198.78
  4. Step 4: Simplify right side
    285.99x = 78,430.64
  5. Step 5: Solve for x
    x = 78,430.64/285.99
  6. Step 6: Final answer
    x = 274.24

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.