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Finding the Fourth Proportional to 210.25, 315.35 and 80.15

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Solution

The fourth proportional to 210.25, 315.35 and 80.15 is: 120.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.25 : 315.35 = 80.15 : x
  2. Step 2: Convert to fraction form
    210.25/315.35 = 80.15/x
  3. Step 3: Cross multiply
    210.25x = 315.35 × 80.15
  4. Step 4: Simplify right side
    210.25x = 25,274.40
  5. Step 5: Solve for x
    x = 25,274.40/210.25
  6. Step 6: Final answer
    x = 120.21

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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.