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Finding the Fourth Proportional to 661.25, 991.88 and 205.25

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Solution

The fourth proportional to 661.25, 991.88 and 205.25 is: 307.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.25 : 991.88 = 205.25 : x
  2. Step 2: Convert to fraction form
    661.25/991.88 = 205.25/x
  3. Step 3: Cross multiply
    661.25x = 991.88 × 205.25
  4. Step 4: Simplify right side
    661.25x = 203,582.34
  5. Step 5: Solve for x
    x = 203,582.34/661.25
  6. Step 6: Final answer
    x = 307.88

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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.