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Finding the Fourth Proportional to 661.70, 912.20 and 521.25

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Solution

The fourth proportional to 661.70, 912.20 and 521.25 is: 718.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.70 : 912.20 = 521.25 : x
  2. Step 2: Convert to fraction form
    661.70/912.20 = 521.25/x
  3. Step 3: Cross multiply
    661.70x = 912.20 × 521.25
  4. Step 4: Simplify right side
    661.70x = 475,481.64
  5. Step 5: Solve for x
    x = 475,481.64/661.70
  6. Step 6: Final answer
    x = 718.58

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.