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Finding the Fourth Proportional to 717.51, 990.38 and 620.31

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Solution

The fourth proportional to 717.51, 990.38 and 620.31 is: 856.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.51 : 990.38 = 620.31 : x
  2. Step 2: Convert to fraction form
    717.51/990.38 = 620.31/x
  3. Step 3: Cross multiply
    717.51x = 990.38 × 620.31
  4. Step 4: Simplify right side
    717.51x = 614,344.17
  5. Step 5: Solve for x
    x = 614,344.17/717.51
  6. Step 6: Final answer
    x = 856.22

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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.