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Finding the Fourth Proportional to 646.05, 891.25 and 380.40

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Solution

The fourth proportional to 646.05, 891.25 and 380.40 is: 524.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.05 : 891.25 = 380.40 : x
  2. Step 2: Convert to fraction form
    646.05/891.25 = 380.40/x
  3. Step 3: Cross multiply
    646.05x = 891.25 × 380.40
  4. Step 4: Simplify right side
    646.05x = 339,031.50
  5. Step 5: Solve for x
    x = 339,031.50/646.05
  6. Step 6: Final answer
    x = 524.78

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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.