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Finding the Fourth Proportional to 210.65, 315.71 and 145.55

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Solution

The fourth proportional to 210.65, 315.71 and 145.55 is: 218.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.65 : 315.71 = 145.55 : x
  2. Step 2: Convert to fraction form
    210.65/315.71 = 145.55/x
  3. Step 3: Cross multiply
    210.65x = 315.71 × 145.55
  4. Step 4: Simplify right side
    210.65x = 45,951.96
  5. Step 5: Solve for x
    x = 45,951.96/210.65
  6. Step 6: Final answer
    x = 218.14

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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.