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Finding the Fourth Proportional to 678.64, 936.24 and 491.72

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Solution

The fourth proportional to 678.64, 936.24 and 491.72 is: 678.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.64 : 936.24 = 491.72 : x
  2. Step 2: Convert to fraction form
    678.64/936.24 = 491.72/x
  3. Step 3: Cross multiply
    678.64x = 936.24 × 491.72
  4. Step 4: Simplify right side
    678.64x = 460,367.93
  5. Step 5: Solve for x
    x = 460,367.93/678.64
  6. Step 6: Final answer
    x = 678.37

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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.