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Finding the Fourth Proportional to 489.90, 675.90 and 315.34

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Solution

The fourth proportional to 489.90, 675.90 and 315.34 is: 435.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.90 : 675.90 = 315.34 : x
  2. Step 2: Convert to fraction form
    489.90/675.90 = 315.34/x
  3. Step 3: Cross multiply
    489.90x = 675.90 × 315.34
  4. Step 4: Simplify right side
    489.90x = 213,138.31
  5. Step 5: Solve for x
    x = 213,138.31/489.90
  6. Step 6: Final answer
    x = 435.06

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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.