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Finding the Fourth Proportional to 643.09, 964.64 and 258.25

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Solution

The fourth proportional to 643.09, 964.64 and 258.25 is: 387.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.09 : 964.64 = 258.25 : x
  2. Step 2: Convert to fraction form
    643.09/964.64 = 258.25/x
  3. Step 3: Cross multiply
    643.09x = 964.64 × 258.25
  4. Step 4: Simplify right side
    643.09x = 249,118.28
  5. Step 5: Solve for x
    x = 249,118.28/643.09
  6. Step 6: Final answer
    x = 387.38

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Double scale
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Similar ratio
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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.