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Finding the Fourth Proportional to 905.21, 1,358.58 and 645.84

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Solution

The fourth proportional to 905.21, 1,358.58 and 645.84 is: 969.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.21 : 1,358.58 = 645.84 : x
  2. Step 2: Convert to fraction form
    905.21/1,358.58 = 645.84/x
  3. Step 3: Cross multiply
    905.21x = 1,358.58 × 645.84
  4. Step 4: Simplify right side
    905.21x = 877,425.31
  5. Step 5: Solve for x
    x = 877,425.31/905.21
  6. Step 6: Final answer
    x = 969.31

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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.