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Finding the Fourth Proportional to 646.32, 891.89 and 380.81

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Solution

The fourth proportional to 646.32, 891.89 and 380.81 is: 525.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.32 : 891.89 = 380.81 : x
  2. Step 2: Convert to fraction form
    646.32/891.89 = 380.81/x
  3. Step 3: Cross multiply
    646.32x = 891.89 × 380.81
  4. Step 4: Simplify right side
    646.32x = 339,640.63
  5. Step 5: Solve for x
    x = 339,640.63/646.32
  6. Step 6: Final answer
    x = 525.50

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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.