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Finding the Fourth Proportional to 643.48, 964.91 and 278.57

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Solution

The fourth proportional to 643.48, 964.91 and 278.57 is: 417.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.48 : 964.91 = 278.57 : x
  2. Step 2: Convert to fraction form
    643.48/964.91 = 278.57/x
  3. Step 3: Cross multiply
    643.48x = 964.91 × 278.57
  4. Step 4: Simplify right side
    643.48x = 268,798.09
  5. Step 5: Solve for x
    x = 268,798.09/643.48
  6. Step 6: Final answer
    x = 417.73

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.