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Finding the Fourth Proportional to 838.82, 1,259.40 and 428.29

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Solution

The fourth proportional to 838.82, 1,259.40 and 428.29 is: 643.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.82 : 1,259.40 = 428.29 : x
  2. Step 2: Convert to fraction form
    838.82/1,259.40 = 428.29/x
  3. Step 3: Cross multiply
    838.82x = 1,259.40 × 428.29
  4. Step 4: Simplify right side
    838.82x = 539,388.43
  5. Step 5: Solve for x
    x = 539,388.43/838.82
  6. Step 6: Final answer
    x = 643.03

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.