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Finding the Fourth Proportional to 307.75, 421.98 and 298.64

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Solution

The fourth proportional to 307.75, 421.98 and 298.64 is: 409.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    307.75 : 421.98 = 298.64 : x
  2. Step 2: Convert to fraction form
    307.75/421.98 = 298.64/x
  3. Step 3: Cross multiply
    307.75x = 421.98 × 298.64
  4. Step 4: Simplify right side
    307.75x = 126,020.11
  5. Step 5: Solve for x
    x = 126,020.11/307.75
  6. Step 6: Final answer
    x = 409.49

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.