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Finding the Fourth Proportional to 684.55, 1,020.32 and 645.63

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Solution

The fourth proportional to 684.55, 1,020.32 and 645.63 is: 962.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.55 : 1,020.32 = 645.63 : x
  2. Step 2: Convert to fraction form
    684.55/1,020.32 = 645.63/x
  3. Step 3: Cross multiply
    684.55x = 1,020.32 × 645.63
  4. Step 4: Simplify right side
    684.55x = 658,754.64
  5. Step 5: Solve for x
    x = 658,754.64/684.55
  6. Step 6: Final answer
    x = 962.32

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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.