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Finding the Fourth Proportional to 739.40, 1,020.80 and 491.06

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Solution

The fourth proportional to 739.40, 1,020.80 and 491.06 is: 677.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    739.40 : 1,020.80 = 491.06 : x
  2. Step 2: Convert to fraction form
    739.40/1,020.80 = 491.06/x
  3. Step 3: Cross multiply
    739.40x = 1,020.80 × 491.06
  4. Step 4: Simplify right side
    739.40x = 501,274.05
  5. Step 5: Solve for x
    x = 501,274.05/739.40
  6. Step 6: Final answer
    x = 677.95

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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.