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Finding the Fourth Proportional to 298.39, 407.95 and 287.05

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Solution

The fourth proportional to 298.39, 407.95 and 287.05 is: 392.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    298.39 : 407.95 = 287.05 : x
  2. Step 2: Convert to fraction form
    298.39/407.95 = 287.05/x
  3. Step 3: Cross multiply
    298.39x = 407.95 × 287.05
  4. Step 4: Simplify right side
    298.39x = 117,102.05
  5. Step 5: Solve for x
    x = 117,102.05/298.39
  6. Step 6: Final answer
    x = 392.45

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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.