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Finding the Fourth Proportional to 998.82, 1,378.28 and 645.26

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Solution

The fourth proportional to 998.82, 1,378.28 and 645.26 is: 890.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.82 : 1,378.28 = 645.26 : x
  2. Step 2: Convert to fraction form
    998.82/1,378.28 = 645.26/x
  3. Step 3: Cross multiply
    998.82x = 1,378.28 × 645.26
  4. Step 4: Simplify right side
    998.82x = 889,342.06
  5. Step 5: Solve for x
    x = 889,342.06/998.82
  6. Step 6: Final answer
    x = 890.39

Related Problems

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Half scale
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Double scale
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Similar ratio
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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.