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Finding the Fourth Proportional to 764.48, 1,055 and 428.40

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Solution

The fourth proportional to 764.48, 1,055 and 428.40 is: 591.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    764.48 : 1,055 = 428.40 : x
  2. Step 2: Convert to fraction form
    764.48/1,055 = 428.40/x
  3. Step 3: Cross multiply
    764.48x = 1,055 × 428.40
  4. Step 4: Simplify right side
    764.48x = 451,962
  5. Step 5: Solve for x
    x = 451,962/764.48
  6. Step 6: Final answer
    x = 591.20

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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.