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Finding the Fourth Proportional to 739.74, 1,020.72 and 420.68

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Solution

The fourth proportional to 739.74, 1,020.72 and 420.68 is: 580.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    739.74 : 1,020.72 = 420.68 : x
  2. Step 2: Convert to fraction form
    739.74/1,020.72 = 420.68/x
  3. Step 3: Cross multiply
    739.74x = 1,020.72 × 420.68
  4. Step 4: Simplify right side
    739.74x = 429,392.96
  5. Step 5: Solve for x
    x = 429,392.96/739.74
  6. Step 6: Final answer
    x = 580.47

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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.