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Finding the Fourth Proportional to 717.39, 990.21 and 620.19

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Solution

The fourth proportional to 717.39, 990.21 and 620.19 is: 856.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.39 : 990.21 = 620.19 : x
  2. Step 2: Convert to fraction form
    717.39/990.21 = 620.19/x
  3. Step 3: Cross multiply
    717.39x = 990.21 × 620.19
  4. Step 4: Simplify right side
    717.39x = 614,118.34
  5. Step 5: Solve for x
    x = 614,118.34/717.39
  6. Step 6: Final answer
    x = 856.05

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Half scale
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Double scale
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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.