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Finding the Fourth Proportional to 211.50, 317.25 and 208.80

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Solution

The fourth proportional to 211.50, 317.25 and 208.80 is: 313.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.50 : 317.25 = 208.80 : x
  2. Step 2: Convert to fraction form
    211.50/317.25 = 208.80/x
  3. Step 3: Cross multiply
    211.50x = 317.25 × 208.80
  4. Step 4: Simplify right side
    211.50x = 66,241.80
  5. Step 5: Solve for x
    x = 66,241.80/211.50
  6. Step 6: Final answer
    x = 313.20

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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.