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Finding the Fourth Proportional to 643.40, 887.96 and 381.48

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Solution

The fourth proportional to 643.40, 887.96 and 381.48 is: 526.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.40 : 887.96 = 381.48 : x
  2. Step 2: Convert to fraction form
    643.40/887.96 = 381.48/x
  3. Step 3: Cross multiply
    643.40x = 887.96 × 381.48
  4. Step 4: Simplify right side
    643.40x = 338,738.98
  5. Step 5: Solve for x
    x = 338,738.98/643.40
  6. Step 6: Final answer
    x = 526.48

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Double scale
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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.