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Finding the Fourth Proportional to 811.70, 1,120.14 and 438.68

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Solution

The fourth proportional to 811.70, 1,120.14 and 438.68 is: 605.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.70 : 1,120.14 = 438.68 : x
  2. Step 2: Convert to fraction form
    811.70/1,120.14 = 438.68/x
  3. Step 3: Cross multiply
    811.70x = 1,120.14 × 438.68
  4. Step 4: Simplify right side
    811.70x = 491,378.05
  5. Step 5: Solve for x
    x = 491,378.05/811.70
  6. Step 6: Final answer
    x = 605.37

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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.