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Finding the Fourth Proportional to 643.20, 964.21 and 278.22

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Solution

The fourth proportional to 643.20, 964.21 and 278.22 is: 417.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.20 : 964.21 = 278.22 : x
  2. Step 2: Convert to fraction form
    643.20/964.21 = 278.22/x
  3. Step 3: Cross multiply
    643.20x = 964.21 × 278.22
  4. Step 4: Simplify right side
    643.20x = 268,262.51
  5. Step 5: Solve for x
    x = 268,262.51/643.20
  6. Step 6: Final answer
    x = 417.07

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1.5x scale

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.