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Finding the Fourth Proportional to 646.12, 891.64 and 380.76

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Solution

The fourth proportional to 646.12, 891.64 and 380.76 is: 525.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.12 : 891.64 = 380.76 : x
  2. Step 2: Convert to fraction form
    646.12/891.64 = 380.76/x
  3. Step 3: Cross multiply
    646.12x = 891.64 × 380.76
  4. Step 4: Simplify right side
    646.12x = 339,500.85
  5. Step 5: Solve for x
    x = 339,500.85/646.12
  6. Step 6: Final answer
    x = 525.45

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1.5x scale

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.