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Finding the Fourth Proportional to 212.90, 317.86 and 189.81

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Solution

The fourth proportional to 212.90, 317.86 and 189.81 is: 283.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.90 : 317.86 = 189.81 : x
  2. Step 2: Convert to fraction form
    212.90/317.86 = 189.81/x
  3. Step 3: Cross multiply
    212.90x = 317.86 × 189.81
  4. Step 4: Simplify right side
    212.90x = 60,332.53
  5. Step 5: Solve for x
    x = 60,332.53/212.90
  6. Step 6: Final answer
    x = 283.39

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.