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Finding the Fourth Proportional to 210.21, 315.39 and 145.28

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Solution

The fourth proportional to 210.21, 315.39 and 145.28 is: 217.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.21 : 315.39 = 145.28 : x
  2. Step 2: Convert to fraction form
    210.21/315.39 = 145.28/x
  3. Step 3: Cross multiply
    210.21x = 315.39 × 145.28
  4. Step 4: Simplify right side
    210.21x = 45,818.28
  5. Step 5: Solve for x
    x = 45,818.28/210.21
  6. Step 6: Final answer
    x = 217.96

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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.