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Finding the Fourth Proportional to 280.90, 421.42 and 98.31

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Solution

The fourth proportional to 280.90, 421.42 and 98.31 is: 147.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.90 : 421.42 = 98.31 : x
  2. Step 2: Convert to fraction form
    280.90/421.42 = 98.31/x
  3. Step 3: Cross multiply
    280.90x = 421.42 × 98.31
  4. Step 4: Simplify right side
    280.90x = 41,429.80
  5. Step 5: Solve for x
    x = 41,429.80/280.90
  6. Step 6: Final answer
    x = 147.49

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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.